The Board collects data from certification-recertification candidates and uses the information to maintain a set of “vital signs” about the Diplomates of the Board. On 1 January 1992, there were 38,880 current Diplomates. Of these, 30,056 (77.3 percent) are residency-trained. California is the state with the largest number of Diplomates — 4331 (11.1 percent). The postal region with the largest number is 981XX in Seattle, Washington.