|If You want to show Your skills in simple arithmetics, then yes, that's right.|
On the other hand, all the files have been created at the beginning, and not much since then, then the simple arithmetic is wrong.
To make real statististics, You would have to show the file creation dates (dir/date/size [...]), and sum up the sizes for each year (write a DCL procedure with an f$search() loop, getting creation date and size using f$file(file,"ALQ") and f$file(file,"CDT"), and sum up the ALQ values to the year given by the CDT date).
What is Your real question ? The disk is almost full, and if You need to create files on a regular rate, then You should acquire an additional disk within half a year!
Joseph Huber, http://www.huber-joseph.de