1989  52.4  51.6  53.2  51.1
 1990  31.6  30.4  25.8  46.6
 1991   6.9   6.2   6.1   9.4
 1992  14.3  16.4  12.9  15.8
 1993  70.8  71.9  70.0  71.8
 1994  70.4  44.6  72.0  88.3
 1995  43.7  26.4  43.2  59.6