Year	Number
1960	0
1965	0
1970	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	4423
1988	31622
1989	94529
1990	184943
1991	291459
1992	497000
1993	690000
1994	1220000
1995	2242000
1996	3990000
1997	4578000
1998	4918000
1999	6315000
2000	8562000
2001	11132000
2002	12670000
2003	14347000
2004	16480000
2005	18420000
2006	19760000
2007	21260000
2008	22120000
2009	22200000
2010	22500000
2011	23789000
2012	24338000
2013	24940000
2014	25060000
2015	25770000
2016	26551000
2017	26660000
2018	27640000
2019	27968000
2020	27013000
2021	27092000
2022	28018000