Don't know, started with 2 dozen new balls at the beginning of the year plus a few left over from the previous year. In the bag at the end of the year were 8 balls, 7 that have been used and one that you can barely read the name on it. I will toss that last ball as I have some others during the year into the shag bag.
Back in the day (60's) it didn't take long to beat a ball out of round, probably no more than 2 rounds.