Year	Number
1990	0
1991	0
1992	900
1993	1300
1994	1900
1995	2340
1996	2279
1997	2350
1998	4980
1999	9580
2000	14503
2001	15854
2002	16759
2003	16900
2004	17085
2005	17150
2006	17390
2007	17500
2008	24402
2009	29949
2010	30587
2011	35465
2012	36000
2013	36780
2014	37600
2015	36624
2016	36570
2017	38000
2018	38500
2019	38750
2020	39000
2021	40000
2022	41000