Year	per 1,000 people
1960	0.778
1965	0.938
1970	0.726
1979	1.693
1981	1.714
1983	1.255
1989	1.862
1991	1.326
1993	1.862
1997	2.1
2001	2.621
2006	2.492
2007	2.326
2010	2.319
2011	2.702
2013	2.341
2014	2.069
2015	2.147
2016	2.158
2017	2.261
2018	2.425
2019	2.617