Server load not getting reduced after installing Cloudflare

I was hoping to reduce the origin server bandwidth by integrating Cloudflare. A few days ago, I set my website’s cache to 5 days, but the server load is not getting reduced. How can I investigate this? Am I missing something in the configuration? Grateful for any help.

I just checked and saw the percent cached stands at about 50%. Is there any way to increase this — which would probably lead to decrease in server load?