It's explained at the bottom:
* The column "Coins that may interest me" displays two figures. The first one is the number of the other member's doubles that you might be interested in, based on your wishes. The second is the total number of the other member's doubles. Similarly, the column "Coins that may interest him/her" displays the number of your doubles that may interest the other member and the total number of your doubles. In these counts, only types have been taken into account, but different years have not.