1961

$  2.93

1962

$  3.01

1963

$  3.12

1964

$  3.15

1965

$  3.16

1966

$  3.32

1967

$  3.44

1968

$  3.58

1969

$  3.81

1970

$  3.96

1971

$  4.12

1972

$  4.36

1973

$  4.61

1974

$  4.99

1975

$  5.47

1976

$  5.97

1977

$  6.35

1978

$  6.98

1979

$  7.67

1980

$  8.56

1981

$  9.39

1982

$10.21

1983

$10.72

1984

$11.14

1985

$11.42

1986

$11.62

1987

$11.61

1988

$11.55

1989

$11.64

1990

$11.83

1991

$12.23

1992

$12.91

1993

$13.44

1994

$13.86

1995

$14.12

1996

$14.32

1997

$14.58

1998

$14.65

1999

$15.22

2000

$15.88

2001

$16.47

2002

$16.89

2003

$17.43

2004

$18.46