APC user cache related question

I’m extremely happy with APc and I know you don’t use it any more but can you explain why I have plenty of free space in my cache, yet my user cache purge rate is extremely high? Should I worry? Should I set the user cache ttl higher?

Check this screen shot to see what I mean => http://screencast.com/t/eeUcO8IL8mas

APC is no longer in development. Last stable release was in 2011.

Also it doesn’t work with PHP 5.5. Plus PHP 5.5 has zend opcache which is better for code-caching. For data caching we now use memcache.