---------------------------
|now |unknown|factor| age | 
---------------------------
|John|  21.01|   0.7| 0.00|
---------------------------
|Jane|  21.01|   1.0| 0.00|
---------------------------
---------------------------
|ago |unknown|factor| age | 
---------------------------
|John|  21.01|   0.5| 7.00|
---------------------------
|Jane|  21.01|   1.0|14.01|
---------------------------