Year	Number
1971	1892002
1972	1785976
1973	2139518
1974	2291203
1975	2461310
1976	2638551
1977	2764761
1978	2855230
1979	2984569
1980	3053784
1981	3088026
1982	3120490
1983	3117212
1984	3167562
1985	3253348
1986	3349211
1987	3440786
1988	3508047
1989	3611860
1990	3657391
1991	3653552
1992	3618326
1993	3632828
1994	3609693
1995	3557852
1996	2972766
1997	2946191
1998	2881620
1999	2855151
2000	2836761
2001	2751086
2002	2663112
2003	2642361
2004	2625398
2005	2620502
2006	2608816
2007	2587750
2008	2574910
2009	2582915
2010	2652426
2011	2681203
2012	2713093
2013	2749260
2014	2716240
2015	2703584
2016	2715242
2017	2711504