Year	Number
1971	137163
1972	153819
1973	169848
1974	194708
1975	158651
1976	155908
1977	171997
1978	168539
1979	170273
1980	175548
1988	180457
1990	204919
1991	234128
2011	50534
2012	7951
2014	8347
2016	10140