Getting the Position of a score while excluding the zero/empty values

Question

I have two different codes for getting the position of a student's score in two subjects. From result columns 'maths' and 'english' containing the scores of different users.

This is what the result for a user looks like

Subject     Score   Rank

English       5         7

Maths          0         1

While this what I hope to get:

Subject     Score   Rank

English       5         7

Maths          0

Here are the codes I used

FOR ENGLISH

<?php $sql="SELECT roll, FIND_IN_SET( English, (SELECT GROUP_CONCAT( English
ORDER BY English DESC ) 
FROM result )
) AS rank
FROM result
WHERE roll = '$roll'";

$result = mysql_query($sql);


$row = mysql_fetch_array($result, MYSQL_ASSOC);

echo $row['rank'] ?>

FOR MATHS

<?php $sql="SELECT roll, FIND_IN_SET( maths, (SELECT GROUP_CONCAT( maths
ORDER BY mathsDESC ) 
FROM result )
) AS rank
FROM result
WHERE roll = '$roll'";

$result = mysql_query($sql);


$row = mysql_fetch_array($result, MYSQL_ASSOC);

echo $row['rank'] ?>