Year	Number
1981	45996
1982	45942
1983	41130
1984	32418
1985	29265
1986	52130
1987	50196
1988	59528
1989	64459
1990	67970
1991	68047
1992	83453
1993	92435
1994	107502
1995	109692
1999	123925
2000	183744
2001	156817
2002	144009
2003	160169
2004	171160
2005	185418
2006	205932
2007	211613
2008	204033
2009	153824
2010	193319
2011	193995
2012	198214
2013	240837
2014	237124
2015	234976
2016	256215
2017	236240