1974     58.7   1060.6
1975     49.1   1065.2
1976     64.5   1203.2
1977     70.4   1328.1
1978     81.1   1496.4
1979     98.7   1741.8
1980     92.6   1912.8
1981    101.3   2144.7
1982     70.9   2039.4
1983     85.8   2114.3
1984    107.6   2335.0
1985     87.6   2331.4
1986     83.1   2220.9
1987    115.6   2378.2
1988    154.6   2596.2
1989    136.3   2745.1
1990    111.6   2810.7
1991     67.5   2761.1
1992     23.2   2890.2
1993     83.9   3015.1
1994    176.6   3258.4