Reporting AX Exchange rates


I am trying to use the AX Excel add-in to report currency exchange rates. (I have also used another third party tool with the same result).

When I try to report on the ExchangeRate table (just this table alone - I have not created links to other tables) I only get a sub-set of the data in the table. It looks like it is only giving one record for each combination of FromCurrency/ToCurrency/Exchange Rate Type. Hence I cannot see historic rates going back.

Anyone else come across this or have any ideas on how to resolve?