Count of Records by Year - Dealers & Auctions

The following graph plots the count of items listed in each year's edition of the Antique Map Price Record over its 24 year history. The counts for dealers and auctions are listed separately. The graph makes it apparent that auction data did not begin to be included until the 1997-1998 volume, but that the proportion of data collected from auctions has increased markedly since then, and in the last two years about 70% of the newly added records come from auctions.