Year	Number
1986	31857
1990	35424
1991	36299
1992	36427
1993	37888
1994	38568
1995	35216
1996	33752
1997	28615
1999	32976
2000	31240
2001	30545
2002	31307
2003	31004
2004	31335
2005	30920
2006	30771
2007	30376
2008	30195
2009	29186
2010	29299
2011	29237
2012	28662
2013	27142
2014	26213
2015	24968
2016	24599
2017	22931
2018	22942
2019	21841
2020	21374
2021	20867