Year	Number
1971	364906
1972	381608
1973	388445
1974	395062
1975	406347
1976	402553
1977	411379
1978	419958
1979	432222
1980	462343
1981	470991
1982	477101
1983	478349
1984	476991
1985	471724
1986	464173
1987	457767
1988	452220
1989	449347
1990	454109
1991	452849
1992	453379
1993	440769
1994	461729
1995	464431
1996	430958
1997	425714
1998	371066
1999	366550
2013	406511
2014	408247
2015	410355
2016	414683
2017	417071
2018	422724
2019	431048
2020	436232
2021	440700