Year	Number
1980	62056
1981	69371
1982	80147
1983	73001
1984	82644
1985	86572
1986	90503
1987	90559
1988	103179
1989	120685
1990	153027
1991	146832
1992	151712
1993	175356
1994	188785
1995	217554
1996	245851
1997	267366
1998	282001
1999	301126
2000	338716
2001	255403
2002	249370
2003	260451
2004	290254
2005	305509
2006	321141
2007	351259
2008	338345
2009	306899
2010	326681
2011	353681
2012	363435
2013	373159
2014	393604
2015	427435
2016	447908
2017	506978