Year	Number
1970	27546
1971	30264
1972	33009
1973	37488
1974	43355
1975	43817
1976	44449
1977	44822
1978	43509
1979	41511
1980	40777
1981	44291
1982	45588
1983	46528
1984	48651
1985	50066
1986	51426
1987	51987
1988	50783
1989	50101
1990	51213
1999	101310
2000	99976
2001	101170
2002	103350
2004	102047
2005	98335
2006	47776
2007	42991
2008	42843
2009	44515
2010	44932
2011	46302
2012	48958
2016	53760
2017	54671