date    field 1 -->  field 2   proportion

01/09  Cuve1      cuve3   50  %

01/10  cuve2     cuve3   50  %

02/10  Cuve3   cuve4   50%

03/10  Cuve2     cuve4   50%

05/10  Cuve4     cuve5   20%

06/11  Cuve1     cuve5   80%

08/12  Cuve5     cuve6     60% 

20/01  cuve6  cuve8  100% 

etc...

in this example:

It is necessary me to find an ascending tracability of the style:

tank 1 is found in tank 6 with X %

or 

Tank 2 is found in tank 5 with y %

I also should find a downward tracability of the style:

In tank 6 find tanks 1 and 2 and 3 and 4 and 5 with each % and each date