Historicals of Fed data, including reserves & loans. http://www.federalreserve.gov/releases/h3/hist/ It's all on their website, but not as clear as % ratios. Try using search engines to find other sources who may have compiled it in a simpler manner. But the general answer is that the long term trend of the reserve % has been down. It's in the rough area of 10%. Can you believe that it was 33% back in the day?
http://www.federalreserve.gov/monetarypolicy/0693lead.pdf click on appendix and scroll down a page, all the history since 1913...