Year	per 1,000 people
1960	0.663009285926819
1970	0.85809999704361
1980	0.857100009918213
1981	0.857599973678589
1990	0.635800004
2000	0.7
2002	0.63
2006	0.6
2012	0.9
2016	1.04
2017	1.04