1989  72.9  75.9  72.9  70.3
 1990  29.6  30.2  17.6  58.5
 1991  23.0  47.9  18.9  11.6
 1992  75.3  83.5  77.3  63.6
 1993  65.2  89.1  60.9  55.2
 1994  87.4  82.8  87.1  92.0
 1995  59.3  68.8  55.6  60.3