Trends in demand and supply of babies

NPR reports on declining foreign adoptions in the U.S. and increased restrictions recently imposed by sending countries.  Foreign adoptions are well measured because State/ICE gets involved with naturalizations.  But although the State Department offers an online database, I can't find data before 1999.  Had international adoptions been trending upward monotonically prior to recent times?  Or had they fluctuated with the economy?