Year	Number
1971	243833
1972	247106
1973	250783
1974	256906
1975	259833
1976	261817
1977	252862
1978	256370
1980	252338
1981	264241
1982	273492
1983	272134
1984	281456
1985	286246
1986	289251
1987	292602
1988	301530
1989	302195
1990	314838
1991	317023
1992	314722
1993	317012
1994	320634
1995	323414
1996	334822
1997	341183
1998	354568
1999	360357
2000	359798
2001	362427
2002	362431
2003	371384
2004	376988
2005	373035
2006	375978
2007	390432
2008	397468
2009	435385
2010	423035
2011	440084
2012	442652
2013	457884
2014	467270
2015	470194
2016	493084
2017	482743
2018	495636
2019	514231
2020	524646
2021	527228