SQL STATEMENT CACHE Informix

Hello, Recently we enabled SQL STATEMENT CACHE in Informix 10.FC8, I have been monitoring the chache since then, one thing I observed is the statements are being removed from the cache well before (50-70MB) the configured max 100MB cache size limit, because the server can still cache another 50-20MB of statements. Any comments on why the statements are being removed well before it reaches max limit. Below are the configured values. STMT_CACHE 2 STMT_CACHE_HITS 2 STMT_CACHE_SIZE 102400 Thank you. -- Chavan