strontium-90 region
6.4   1
5.8   1
6.5   1
7.7   1
6.1   1
7.1   2
9.9   2
11.2  2
10.5  2
8.8   2
5.7   3
5.9   3
8.2   3
6.6   3
5.1   3
9.5   4
12.1  4
10.3  4
12.4  4
11.7  4