X1973 X1974 X1975 X1976
2.8 3.6 1.4 2
5.9 1.7 0.9 2.2
3.3 5.1 1.1 0.9
4.4 2.2 3.2 1.1
1.7 2.1 0.8 0.5
3.8 4.1 1.5 1.2
6.6 4.7 2.8 1.4
3.1 2.7 1.4 3.5
0 1.3 0.5 1.2