"Nothing in Biology Makes Sense Except in the Light of Evolution" - Theodosius Dobzhansky
There is grandeur in this view of life, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
The player with the most building parts on the wonder earns the highest value in victory points shown on that row of the table. The player with the second most building parts on the wonder earns the second highest value in victory points shown.
In the case of only one player on the wonder I would interpret it as that player gets the highest value shown on the table and there is no player with the second most building parts thus the second highest value is not awarded.