1985     17.84
     1986     18.46
     1987     24.09
     1988     19.03
     1989     25.32
     1990     29.95
     1991     34.13
     1992     33.56
     1993     25.94
     1994     27.94
     1995     27.00
     1996     34.19
     1997     39.50
     1998     57.06
     1999     54.56
     2000     46.31