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!

another idea:
capture the desired output in a file for as much duration as you want (13 minutes in your case) (append to the file, don't overwrite it)
finally, analyze the data in the file to determine min and max values

pros:
you retain the data so that you can analyse it later
capturing the data and analysis of data are separated

cons:
you may end up filling disk space with the data files

Actually, I want to do it all in one script so I can see the largest and smallest users simultaneously with the output. Thanks for the input, though. Any other ideas?