what was the last time the fed changed reserve requirements?

[Daal]

is there a historical data anywhere?

 

[Hydroblunt]

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?

 

[2cents]

http://www.federalreserve.gov/monetarypolicy/0693lead.pdf click on appendix and scroll down a page, all the history since 1913...