Unlike the Alan Guttmacher Institute, which bases its numbers on actual surveys of abortion providers, the Centers for Disease Control (CDC) relies on data reported by 50 state health departments and the health departments of Washington, D.C., and New York City. In the past, the CDC has admitted that this procedure probably leads them to undercount the total number of abortions (typically, 11%-13% lower than figures obtained by Guttmacher), and specifically mentions in this latest report that 36% of abortions were reported from states which did not have centralized reporting. Still, since CDC numbers generally parallel those reported by Alan Guttmacher, rising or falling at relatively the same rate, CDC data is still considered useful for interpreting trends, especially in abortion rates and ratios. The Alan Guttmacher Institute has not released any comprehensive statistics of its own since 1992 (other than an estimate of 1,435,000 abortions for 1994 reported in USA Today in 1996), but is conducting a new survey for 1995 and 1996 which it expects to publish in late 1998.