A = {
1 '1-2 2004' 0.256 0.385
1 '3-4 2004' 0.268 3.0394
1 '5-6 2004' 0.0504 0.6475
1 '7-8 2004' 14.0985 148.2583
1 '9-10 2004' 0.1128 1.1506
1 '11-12 2004' NaN 148.2583
1 '1-2 2005' NaN 148.2583
1 '3-4 2005' 2.5852 34.0146
1 '5-6 2005' 0.322 3.2846
1 '7-8 2005' 14.0985 148.2583
1 '9-10 2005' 2.5852 NaN
1 '11-12 2005' 0.2938 2.854
2 '1-2 2004' 0.256 0.385
2 '3-4 2004' 0.268 3.0394
2 '5-6 2004' 0.0504 0.6475
2 '7-8 2004' 14.0985 148.2583
2 '9-10 2004' 0.1128 1.1506
2 '11-12 2004' NaN 148.2583
2 '1-2 2005' NaN 148.2583
2 '3-4 2005' 2.5852 34.0146
2 '5-6 2005' 0.322 3.2846
2 '7-8 2005' 14.0985 148.2583
2 '9-10 2005' 2.5852 NaN
2 '11-12 2005' 0.2938 2.854
3 '1-2 2004' 0.256 0.385
3 '3-4 2004' 0.268 3.0394
3 '5-6 2004' 0.0504 0.6475
3 '7-8 2004' 14.0985 148.2583
3 '9-10 2004' 0.1128 1.1506
3 '11-12 2004' NaN 148.2583
3 '1-2 2005' NaN 148.2583
3 '3-4 2005' 2.5852 34.0146
3 '5-6 2005' 0.322 3.2846
3 '7-8 2005' 14.0985 148.2583
3 '9-10 2005' 2.5852 NaN
3 '11-12 2005' 0.2938 2.854}