PERIOD	VALUE
1975	155
1976	287
1977	171
1978	260
1979	339
1980	586
1981	1033
1982	1317
1983	1663
1984	3108
1985	3260
1986	4580
1987	6337
1988	9525
1989	15481
1990	17831
1991	17079
1992	16559
1993	14796
1994	14931
1995	14943
1996	15932