Going to Moody's will only give you today's rate (depending on what time of day you go there, it might be yesterday's). In order to see a rate at any other point in time, you must pay an $8,000 annual subscription fee.
The SOA had made arrangements with Moody's to display the end-of-month historical rates on their website. Note this is not the monthly average, it is still only a daily rate, once a month. It would be a violation of copyright laws to display this elsewhere without a contract with Moody's to do this.
Having said that, the rates have been removed from the SOA website. Don't know if it is temporary or not.
Your topic title is "FASB Disclosure Rates." The Moody's Aa Index is typically not an appropriate proxy for the discount rate (that index has too much recognition of call and other features, only 18 bonds in the index -- half corporate, half utility, and they are constantly changed -- meaning you don't know what the index represents). The correct rates to use should be based on actual cashflows of the plan and matching spot rates for those cashflows. An example of the appropriate spot rates are at:
http://www.soa.org/sections/pendis.htmlWith an explanation of how they were derived at:
http://www.soa.org/library/sectionnews/pen...ion/PSN9406.pdf