country year income charge
1 1948 36
1 1949 59
1 1950 35 1
1 1951 43
1 1952 23
2 1950 50
2 1951 54 1
2 1952 59
2 1953 77
请问如何实现如下结果。
country year income charge
1 1948 36 0
1 1949 59 0
1 1950 35 1
1 1951 43 1
1 1952 23 1
2 1950 50 0
2 1951 54 1
2 1952 59 1
2 1953 77 1