In [93]: df
Out[93]:
        Data
0 1982-01-31
1 1982-02-28
2 1982-03-31
3 1982-04-30
4 1982-05-31

In [94]: df['Data'].dt.year
Out[94]:
0    1982
1    1982
2    1982
3    1982
4    1982
Name: Data, dtype: int64