Who was the Professor before Quirrell?

The first book has a scentence that states,

"...He was fine while he was studyin' outta books but then took a year off ter get some first-hand experience..."

This is just a snippet out of a whole passage, but is the most important part.

If Quirrell took a year off, this must mean that he was there for more than one year before, however Tom Riddle cursed the DADA position when he was denied as a teacher by Dumbledore. He cursed the position so that no teacher could stay in the position for more than one year.