Year	per 1,000 people
1990	2.9109
1991	2.8961
1992	2.9409
1993	2.9571
1994	3.0191
1995	3.0496
1996	3.1175
1997	3.161
1998	3.226
1999	3.2903
2000	3.2998
2011	4.618
2012	4.697
2013	4.719
2014	4.877
2015	5.051
2016	4.277
2017	4.33
2018	4.386
2019	4.434