I'm using MySQL version 5.5.25a

I need to get the total time difference from startTime and endTime

So if I have
startTime = 14:00
endTime = 15:30

I need the result to show as 1.5

I believe I am on the right track just not sure how to show the result as I need it...

The fields are TIMESTAMP

Code:
SELECT
    TIME_FORMAT(SEC_TO_TIME(UNIX_TIMESTAMP(endTime) - UNIX_TIMESTAMP(startTime)), '%H.%i') AS totalTime
FROM
    table

Right now my result would be 01.30

Thanks