Year	Number
1970	3260266
1971	3283285
1972	3248957
1973	3140065
1974	3062163
1975	3076028
1976	2960857
1977	2790920
1978	2695898
1979	2337343
1980	2263142
1981	2070722
1982	2057960
1983	2084864
1984	2141892
1985	2078325
1986	2165592
1987	2196267
1988	2335093
1989	2609287
1990	2534274
1991	2486356
1992	2174075
1993	2029433
1994	2136664
1995	2150301
1996	2035645
1997	2177790
1998	1473828
1999	1071974
2000	907636
2001	797904
2002	688082
2003	716646
2004	978149
2005	773190
2006	1101349
2007	1123616
2008	658571
2009	756928
2010	876410
2011	855376
2012	859666
2013	978789
2014	1015959
2015	990182
2016	968404
2017	921319
2018	1151204