Hits to Insert Ratio and Insert to Prune Ratio
Hit:Insert     0.47:1


means "every inserted entry was requested 0.5 times, before it was removed". (Yes, that's not good.)

Insert:Prune    1.96:1


means "for every second insert, I had to prune/remove one existing entry". An old rule of thumb states "a value between 10 and 20 percent is acceptable", while your value is 50%.

Another helpful number is the query cache hit rate, which is

((Qcache_hits/(Qcache_hits+Qcache_inserts+Qcache_not_cached))*100)


in your case thats roughly 9%, meaning only 9% of the queries can be satisfied by the query cache.

Recommendations reach from "give the query cache more RAM" over "play around with query_cache_min_res_unit" to "give the query cache less RAM"... which is not a really helpful advice.

Since you have set query_cache_size=8M I would recommend to raise this value. 8 Megabytes seems very low to me.