Year	Number
1980	459937
1981	439683
1982	462898
1983	474447
1984	509713
1985	593962
1986	656848
1987	699873
1988	775893
1989	849839
1990	899850
1991	866153
1992	924089
1993	996718
1994	1050381
1995	1124625
1996	1119300
1997	1127583
1998	1154828
1999	1265424
2000	1479603
2001	1249352
2002	1191330
2003	1212954
2004	1269360
2005	1326905
2006	1359975
2007	1453662
2008	1383527
2009	1279600
2010	1356889
2011	1408051
2012	1421945
2013	1450072
2014	1509192
2015	1609077
2016	1673244
2017	1805679