Question on Broker reserve/buffer funds

A while back I saw a chart of futures brokers with information on their size and the amount of funds they held as a buffer as a safeguard for clients funds should something happen to cause the broker to lose a large sum. I thought it was somewhere here on ET, but can not find it. Any guidance appreciated.

 

This is the Financial Data for FCMs: http://www.cftc.gov/MarketReports/financialfcmdata/index.htm

 

That was it. Thank you!