*** Original:
0: undef column2 column3
1: undef column2 column3
2: undef column2 column3
3: undef column2 column3
4: undef column2 column3
5: 1     column2 column3
6: 2     column2 column3
7: 12    column2 column3
8: 100   column2 column3
9: 234   column2 column3
*** Filtered:
0: 1     column2 column3
1: 12    column2 column3
2: 100   column2 column3