Table Footer add total of column (Column name TL and NLA)

Question

<tbody>

@{int srno2 = 0;}

@foreach (College.Core.ViewModels.SGPA.ExamsViewModel _Exams in _subject.GetExams())

{

srno2 += 1;

<tr>

<td>@srno2</td>

<td>@_Exams.ExamType</td>

<td>@_Exams.ObtainedMark</td>

<td>@_Exams.OutOfMarks</td>

@if(@_Exams.TotalLectureConducted == null)

{

<td>0</td>

}

else

{

<td>@_Exams.TotalLectureConducted</td>

}

@if(@_Exams.NoOfLectureAttended == null)

{

<td>0</td>

}

else

{

<td>@_Exams.NoOfLectureAttended</td>

}

@if(@_Exams.AverageAttendance == null)

{

<td>0%</td>

}

else

{

<td>@_Exams.AverageAttendance%</td>

}

</tr>

}

</tbody>

<tfoot>

<tr>

<td colspan="4" align="right">Total</td>

<td>SUM-TotalLectureConducted</td>

<td>SUM-NoOfLectureAttended</td>

<td>(SUM-TL/SUM-NLA)*100</td>

</tr>

</tfoot>