How to find the library cache hit ratio

Library Cache Hit Ratio.

select sum(pins) Executions, sum(pinhits) "Execution Hits",
((sum(pinhits) / sum(pins)) * 100) phitrat,
sum(reloads) Misses,
((sum(pins) / (sum(pins) + sum(reloads))) * 100) hitrat
from v$librarycache;