Why are a incomplete number of records available in a HTML table created using Editor?

Link to test case: Below are the files:
table.personnel_w_termination.php

<?php

/*
 * Editor server script for DB table personnel_w_termination
 * Created by http://editor.datatables.net/generator
 */

// DataTables PHP library and database connection
include( "lib/DataTables.php" );

// Alias Editor classes so they are easy to use
use
    DataTables\Editor,
    DataTables\Editor\Field,
    DataTables\Editor\Format,
    DataTables\Editor\Mjoin,
    DataTables\Editor\Options,
    DataTables\Editor\Upload,
    DataTables\Editor\Validate,
    DataTables\Editor\ValidateOptions;

// The following statement can be removed after the first run (i.e. the database
// table has been created). It is a good idea to do this to help improve
// performance.
$db->sql( "CREATE TABLE IF NOT EXISTS `personnel_w_termination` (
    `idPersonnel` int(10) NOT NULL auto_increment,
    `FName` varchar(255),
    `LName` varchar(255),
    `HireDate` date,
    `Termination` date,
    PRIMARY KEY( `idPersonnel` )
);" );

// Build our Editor instance and process the data coming from _POST
Editor::inst( $db, 'personnel_w_termination', 'idPersonnel' )
    ->fields(
        Field::inst( 'FName' ),
        Field::inst( 'LName' ),
        Field::inst( 'HireDate' )
            ->validator( Validate::dateFormat( 'm/d/y' ) )
            ->getFormatter( Format::dateSqlToFormat( 'm/d/y' ) )
            ->setFormatter( Format::dateFormatToSql( 'm/d/y' ) ),
        Field::inst( 'Termination' )
            ->validator( Validate::dateFormat( 'm/d/y' ) )
            ->getFormatter( Format::dateSqlToFormat( 'm/d/y' ) )
            ->setFormatter( Format::dateFormatToSql( 'm/d/y' ) )
    )
    ->process( $_POST )
    ->json();

**This file produces 231 records but the MySQL database has 277 records. **

Next File: table.personnel_w_termination.js

/*
 * Editor client script for DB table personnel_w_termination
 * Created by http://editor.datatables.net/generator
 */

(function($){

$(document).ready(function() {
/*  $.fn.dataTable.moment('YYYY, MM, DD');
    $.fn.dataTable.moment('MM, DD. YYYY ');
 */
    var editor = new $.fn.dataTable.Editor( {
        ajax: 'php/table.personnel_w_termination.php',
        table: '#personnel_w_termination',
        fields: [
            {
                "label": "FName:",
                "name": "FName"
            },
            {
                "label": "LName:",
                "name": "LName"
            },
            {
                "label": "HireDate:",
                "name": "HireDate",
                "type": "datetime",
                // "format": "YYYY/MM/DD"
                "format": "MM/DD/YY"
            },
            {
                "label": "Termination:",
                "name": "Termination",
                "type": "datetime",
                "format": "MM/DD/YY"
                // "format": "YYYY/MM/DD"
            }
        ]
    } );

    var table = $('#personnel_w_termination').DataTable( {

        dom: 'QBfrtip',
        ajax: 'php/table.personnel_w_termination.php',
        columns: [
            {
                "data": "FName"
            },
            {
                "data": "LName"
            },
            {
                "data": "HireDate"
/*              "type": "date",
                "format": "MM\/DD\/YY"
 */         },
            {
                "data": "Termination"
            }
        ],
        select: true,
        // lengthChange: false,
        buttons: [
            { extend: 'create', editor: editor },
            { extend: 'edit',   editor: editor },
            { extend: 'remove', editor: editor },
            { 
                extend: 'collection',
                text: 'Export',
                buttons: [
                    'copy',
                    'excel',
                    'csv',
                    'print'
        
                ]
            },
            { 
                extend: 'print',
                //autoPrint: false,
                text: 'Print Results',
                title: 'Personnel',
                exportOptions:
                {
                    columns: ':visible'
                },
                //title: 'Customisation of the print view window',
                messageTop: 'Employee Hire / Termination ',
                //messageTop: 'This print was produced using the Print button for DataTables',
               customize: function ( win ) {
                   $(win.document.body)
                       .css( 'font-size', '16pt' )
                       .css( 'color', 'blue')
                       .css('font-variant','small-caps')
                       .prepend(
                           // '<img src="http://datatables.net/media/images/logo-fade.png" style="position:absolute; top:0; left:0;" />'
                       );
       
                   $(win.document.body).find( 'table' )
                       .addClass( 'compact' )
                       .css( 'font-size', '14pt' )
                       .css( 'color', 'black')
                       .css( 'text-align', 'center')
                       .css('background-color', 'bisque')
                       .css('border', 'blue');
       
                   $(win.document.body).find('thead')
                           .css('font-variant', 'small-caps')
                           .css('color', 'firebrick');
                           
           }
       
            }   
        ]
    } );
} );

}(jQuery));

Debugger code (debug.datatables.net): None
Error messages shown: No errors produced
Description of problem: These files produce a HTML table with 231 files paginated over 24 pages. However there are 277 records in the MySQL database table. Why are a limited number of records resulting?

Thank you for any help.
John Chintall

Edited by Allan - Syntax highlighting. Details on how to highlight code using markdown can be found in this guide.