Year	Number
1971	75513
1972	81671
1973	88299
1974	94039
1975	101876
1976	111820
1977	125120
1978	135479
1979	139443
1980	145626
1981	148983
1982	154772
1983	160188
1984	165696
1985	170616
1986	172975
1987	176378
1988	181607
1989	185464
1990	189560
1991	124996
1992	114641
1993	122930
1994	129956
1995	131264
1996	141841
1997	143286
1998	142308
1999	139691
2000	140182
2001	141419
2002	148712
2003	154056
2004	158271
2005	202826
2006	203423
2007	211576
2008	208608
2009	210665
2010	213733
2011	223688
2012	230280
2013	239231
2014	252585
2015	264185
2016	271285
2017	275334
2018	279956
2019	276318
2020	278958
2021	265113