UNIX for Dummies Questions & Answers

Hey. This is pretty easy stuff but I'm learning the basics of Unix at the moment so keep that in mind. I have to:

1) Write a C-shell script to monitor user activity on the server for 13 minutes.
2) Then print the smallest and largest number of users during these 13 minutes.

I have this:
1)
set number = ` who | wc -l `
@ x = 1

while ( $x < 14 )
echo " Cycle $x : number of users = $number "
@ x++
sleep 60
end

2)
But I having a hard time figuring out how to do the second part where I have to print the largest and smallest numbers. Any help will be appreciated!