a   b   i  x                   y                   ab   oa ob
pan pan 1  0.3467901443380824  0.7268028627434533  2002 1  1
eks pan 2  0.7586799647899636  0.5221511083334797  2002 1  1
wye wye 3  0.20460330576630303 0.33831852551664776 2002 1  1
eks wye 4  0.38139939387114097 0.13418874328430463 2002 1  1
wye pan 5  0.5732889198020006  0.8636244699032729  2002 1  1
zee pan 6  0.5271261600918548  0.49322128674835697 2003 1  1
eks zee 7  0.6117840605678454  0.1878849191181694  2003 1  1
zee wye 8  0.5985540091064224  0.976181385699006   2003 1  1
hat wye 9  0.03144187646093577 0.7495507603507059  2003 1  1
pan wye 10 0.5026260055412137  0.9526183602969864  2003 1  1
