jQuery code to get checkbox length while using jQuery DataTables

I am getting wrong value while fetching the checkbox length using jQuery and jQuery DataTables.

HTML:

<table class="table table-bordered" id="dataTables-show-productList">
   <thead>
      <tr>
         <th width="5px"><input type="checkbox" name="Select All" class="chkSelectAll" /></th>
         <th>Product Information</th>
      </tr>
   </thead>
   <tbody>                 
    <c:forEach var="masterListVar" items="${masterList}">                   
      <tr>
         <td width="1%" align="center">
         <c:if test="${masterListVar.saveFlag}">
            <input type="checkbox" path="selectChecked" checked class="Projection_test" value="${masterListVar.productId}"/>
         </c:if>
         <c:if test="${!masterListVar.saveFlag}">
            <input type="checkbox" path="selectChecked" class="Projection_test" value="${masterListVar.productId}"/>
         </c:if>
         </td>
         <td>${masterListVar.productInfo}</td>
      </tr>
   </c:forEach>   
   </tbody>
</table>

JavaScript:

$('#dataTables-show-productList').DataTable({
   width:'100%'
   , responsive : true
   , "bSort" : false 
});


$('.chkSelectAll').click(function () {
   $('.Projection_test').prop('checked', $(this).is(':checked'));
});

$('.Projection_test').click(function () {
   if ($('.Projection_test:checked').length == $('.Projection_test').length) {
     $('.chkSelectAll').prop('checked', true);
   }
   else {
     $('.chkSelectAll').prop('checked', false);
   }
});


$('#FavouriteList').click(function (e) {
   var selectedRow = $('.Projection_test');

   alert($('.Projection_test:checked').length);
   e.preventDefault();
});

When paginating, while selecting only 12 values. in the alert it showing only 2 when i kept in the 2 page and testing.

via Chebli Mohamed