The year-by-year budget since Reagan started the program (which he called the Strategic Defense Initiative, and which was later renamed National Missile Defense, then Ballistic Missile Defense, now Missile Defense) is as follows:

FY 1985—$1.4 billion
FY 1986—2.8 billion
FY 1987—3.2 billion
FY 1988—3.6 billion
FY 1989—3.7 billion
FY 1990—4.0 billion
FY 1991—2.9 billion
FY 1992—4.1 billion
FY 1993—3.8 billion
FY 1994—2.8 billion
FY 1995—2.8 billion
FY 1996—3.4 billion
FY 1997—3.7 billion
FY 1998—3.8 billion
FY 1999—3.5 billion
FY 2000—3.6 billion
FY 2001—4.8 billion
FY 2002—7.8 billion
FY 2003—7.4 billion

(Source: Missile Defense Agency, Department of Defense)