Year	Number
1990	51767
1991	48348
1992	45024
1993	41676
1994	38364
1995	35193
1996	32590
1997	30661
1998	28864
1999	27259
2000	26059
2001	24827
2002	23604
2003	22750
2004	22076
2005	21418
2006	20742
2007	20096
2008	19728
2009	19255
2010	18462
2011	17489
2012	16640
2013	15945
2014	15496
2015	15234
2016	14979
2017	14699
2018	14196
2019	13616
2020	13102
2021	12766
2022	12550