Greatings from Pretoria(RSA)

I ran STATSPACK(8.1.6) on a TEST db and found these results in the output:

SGA breakdown difference for DB:xxx Instance: x Snaps:1-7

Name Begin value / End value / Difference
------------------------------- ----------- ------------
dictionary cache 4,630,636 / 3,172,060/ -1,458,576
library cache 3,755,860 / 2,583,232 / -1,172,628
sql area 4,223,076 / 6,873,392/ 2,650,316

Do I need to get worried? What do you recommend I look at/change?

Thanks a million