assoaciative array with column sum associative array

 <?php

$attendance=array(

array("month"=>"june", "present_days"=>"13","pdays"=>"20"),

array("month"=>"july", "present_days"=>"16","pdays"=>"20"),

array("month"=>"aug", "present_days"=>"11","pdays"=>"20"),

array("month"=>"sept", "present_days"=>"20","pdays"=>"20")

);

$attendance_count=count($attendance);

echo $attendance_count; // o/p 4

echo "<br />";

?>

<?php

$present_days=null;

$absent_days=null;

$total_days=null;

$total_marks=null;

$total_absent_days=null;

$total_present_days=null;

for($i=0;$i<$attendance_count;$i++)

{

echo $attendance[$i]["month"]." ";

echo $attendance[$i]["present_days"]." ";

$total_present_days=$total_present_days+$attendance[$i]["present_days"];

echo $attendance[$i]["pdays"] - $attendance[$i]["present_days"] . " ";

$total_absent_days=$total_absent_days+$attendance[$i]["pdays"] - $attendance[$i]["present_days"] ;

echo $attendance[$i]["pdays"]." ";

$total_days=$total_days + $attendance[$i]["pdays"];

echo $attendance[$i]["present_days"]/10 . "<br /> ";

$total_marks=$total_marks+$attendance[$i]["present_days"]/10;

}

echo "total";

echo "<br /> ------".$total_present_days." ".$total_absent_days." ".$total_days." ".$total_marks;

?>

 o/p

4
june 13 7 20        1.3
july 16 4 20         1.6
aug 11 9 20         1.1
sept 20 0 20        2

total
------60 20 80     6