$ sar -r
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 freemem freeswap
01:00:00    2135   401922
02:00:02    2137   401949
03:00:00    2137   402006
04:00:00    2139   401923
05:00:01    2138   402033
06:00:00    2137   401919

Average     2500   399914