Year	Number
1970	10159
1971	10455
1972	10371
1973	10552
1974	11052
1975	11351
1978	12795
1981	16566
1982	17085
1983	16822
1984	17009
1985	15232
1986	13587
1990	14749
1991	14825
1993	16570
1998	13661
1999	14710
2000	14524
2001	14127
2002	14567
2003	15743
2004	14032
2006	13938
2007	14580
2008	14632
2009	14676
2010	14777
2011	14874
2012	14784
2013	14840
2014	14927
2015	15800
2019	15324
2020	14486
2021	17099
2022	15664