Year	per 1,000 people
1960	0.009
1965	0.014
1970	0.012
1975	0.012
1980	0.011
1981	0.011
1984	0.013
1988	0.031
1994	0.029
1996	0.025
1997	0.023
1998	0.021
1999	0.02
2000	0.021
2001	0.028
2002	0.029
2003	0.027
2004	0.027
2005	0.032
2006	0.027
2007	0.022
2008	0.025
2009	0.025
2018	0.076
2020	0.104