Year	Number
1972	29.11245
1973	29.35881
1974	27.49734
1975	25.56224
1977	26.1424
1978	26.88693
1985	16.98705
1986	15.79482
1987	15.27401
1988	15.65904
1989	14.24636
1990	14.01134
1992	13.87415
1993	9.78771
1994	10.45771
1995	10.49849
1999	5.54146
2000	5.42027
2001	5.52632