Year	Number
1987	32000
1988	33800
1989	36300
1990	66400
1991	66300
1992	96000
1993	43500
1994	41900
1995	45800
1996	41300
1997	33100
1998	32000
1999	33100
2000	16109
2001	18805
2002	24592
2003	27471
2004	28970
2005	25789
2006	30232
2007	29980
2008	29530
2009	27692
2017	22435
2018	24313
2019	21500
2020	25563
2021	30115