Year	per 1,000 people
1980	6.67199993133545
1984	6.82000017166138
1985	6.76800012588501
1986	6.69999980926514
1987	6.65899991989136
1988	7.65700006484985
1989	7.44500017166138
1990	7.1599998474
2011	3.85
2012	3.8