Year	Number
1971	101713
1972	103644
1973	108490
1974	111776
1975	116300
1976	82233
1977	89669
1978	93916
1979	100438
1980	103119
1981	108268
1982	109736
1983	113708
1984	125210
1985	123868
1986	123328
1987	120809
1988	119345
1989	119187
1990	118225
1991	120885
1992	130341
1993	129589
1994	136553
1995	133008
1996	135217
1997	140632
1998	136442
1999	147085
2000	165446
2001	177161
2002	181129
2003	189273
2004	119996
2005	123105
2006	124568
2007	125989
2008	126504
2009	127484
2010	131388
2011	134093
2012	134190
2013	252191
2014	251652
2015	257764
2016	258482
2017	261660