Year	Number
1981	36864
1982	37375
1983	38062
1984	38786
1985	39336
1986	39796
1987	40124
1988	39285
1989	38987
1990	38763
1991	38632
1992	38439
1993	38301
1994	38637
1995	39577
1996	39428
1997	39287
1998	38340
1999	37301
2000	36197
2001	35021
2002	33965
2003	33249
2004	32270
2005	31546
2006	30944
2007	30612
2008	30991
2009	31329
2010	31606
2011	31590
2012	31590
2013	31578
2014	30921
2015	30866
2016	30910
2017	30956
2018	30979
2019	30921
2020	30845
2021	30702
2022	30589