Improve PHP execution speed - php

Question

Please how do i improve the speed of php code. I have over 1580 lines of code that needs to be process about 103,000 data set. Presently this code takes more than 5 minutes to process 1 data set. It contains 30 for loops and 168 conditional statement.
$tnu =0; $tcp=0; $tnup = 0;
if($SsNoCourses[$sessionCounter] != 0){
//echo $SsNoCourses[$sessionCounter]."</br>";
$secondSemesterExist = "True";
$actualSemesterCounter = $actualSemesterCounter + 1;
$lastComputedSemesterId = $actualSemesterCounter;
for($i = 0; $i<$noOfCoursesS; $i++){
if ($sessionCounter == 1){
$tnu = $tnu + $SsY1Courses[$i][2];
$tcp = $tcp + $SsY1Courses[$i][2]*$SsY1Courses[$i][4];
if ($SsY1Courses[$i][4] != 0){$tnup = $tnup + $SsY1Courses[$i][2];}
}else if ($sessionCounter == 2){
$tnu = $tnu + $SsY2Courses[$i][2];
$tcp = $tcp + $SsY2Courses[$i][2]*$SsY2Courses[$i][4];
if ($SsY2Courses[$i][4] != 0){$tnup = $tnup + $SsY2Courses[$i][2];}
}else if ($sessionCounter == 3){
$tnu = $tnu + $SsY3Courses[$i][2];
$tcp = $tcp + $SsY3Courses[$i][2]*$SsY3Courses[$i][4];
if ($SsY3Courses[$i][4] != 0){$tnup = $tnup + $SsY3Courses[$i][2];}
}else if ($sessionCounter == 4){
$tnu = $tnu + $SsY4Courses[$i][2];
$tcp = $tcp + $SsY4Courses[$i][2]*$SsY4Courses[$i][4];
if ($SsY4Courses[$i][4] != 0){$tnup = $tnup + $SsY4Courses[$i][2];}
}else if ($sessionCounter == 5){
$tnu = $tnu + $SsY5Courses[$i][2];
$tcp = $tcp + $SsY5Courses[$i][2]*$SsY5Courses[$i][4];
if ($SsY5Courses[$i][4] != 0){$tnup = $tnup + $SsY5Courses[$i][2];}
}else if ($sessionCounter == 6){
$tnu = $tnu + $SsY6Courses[$i][2];
$tcp = $tcp + $SsY6Courses[$i][2]*$SsY6Courses[$i][4];
if ($SsY6Courses[$i][4] != 0){$tnup = $tnup + $SsY6Courses[$i][2];}
}else if ($sessionCounter == 7){
$tnu = $tnu + $SsY7Courses[$i][2];
$tcp = $tcp + $SsY7Courses[$i][2]*$SsY7Courses[$i][4];
if ($SsY7Courses[$i][4] != 0){$tnup = $tnup + $SsY7Courses[$i][2];}
}else if ($sessionCounter == 8){
$tnu = $tnu + $SsY8Courses[$i][2];
$tcp = $tcp + $SsY8Courses[$i][2]*$SsY8Courses[$i][4];
if ($SsY8Courses[$i][4] != 0){$tnup = $tnup + $SsY8Courses[$i][2];}