Year	Number
1975	77048
1976	90000
1977	100000
1978	115000
1979	130000
1980	146261
1981	159050
1982	171174
1983	181279
1984	197060
1985	213951
1986	236304
1987	259611
1988	270694
1989	287912
1990	314052
1991	331776
1992	338699
1993	367400
1994	338899
1995	357000
1996	342023
1997	350900
1998	368430
1999	370636
2000	376092
2001	388222
2002	394770
2003	396168
2004	416430
2005	440383
2006	458876
2007	482005
2008	494503
2009	498328
2010	489052
2011	502020
2012	488853
2013	461277
2014	443184
2015	408037
2016	382149
2017	362288
2018	331140
2019	298855
2020	299000
2021	299000