1989  69.7  74.2  68.1  69.8
 1990  23.2  22.1  12.9  49.5
 1991  22.0  55.5  14.7  11.4
 1992  69.3  80.0  74.2  48.3
 1993  52.3  86.3  46.7  37.1
 1994  91.1  88.5  91.2  93.3
 1995  66.4  73.7  65.2  63.0