[R] stuck on making a line graph across time, with 4 categories

[Christopher W. Ryan]

I can't seem to find just what I'm looking for in R help, Everitt and
Hothorn HSAUR, Murrell's book, or the R graphics gallery at
http://addictedtor.free.fr/graphiques/.  Probably not looking
efficiently, but anyway,

If my data look like this:

> head(data)
      cat startyear studentid
1   other      2001        12
2     UHS      2001        17
3 Lourdes      2001        10
4 Endwell      2001         3
5   other      2002        13
6     UHS      2002        19
>

What is the easiest way to make a line graph like this (made this one in
Stata):

http://bingweb.binghamton.edu/~cryan/Workload.png

Thank you.

--Chris
-- 
Christopher W. Ryan, MD
SUNY Upstate Medical University Clinical Campus at Binghamton
40 Arch Street, Johnson City, NY  13790
cryanatbinghamtondotedu
PGP public keys available at http://home.stny.rr.com/ryancw/

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