Has the caching rate reduced in the recent times

Has Google reduced the frequency of caching now days? I am finding few of my sites with cache not updated for long even after updating the content and simultaneously the site maps.

 

I am getting the same thing, who know what is happening?

 

Same here. One of our very high traffic sites that rarely went more then a couple days between caches is 1 week+ now for all the pages since the last cache. Most of the content has changed since our last cache as well as the sitemap and robots.txt changing like usual. They've crawled them, but not updated the cache as well as the metas in the index on the pages that were changed.