A tornado severely damaged one of Down Town Dig’s retail clothing store, destroying all the inventory in the store. Down Town Dig’s ending store inventory last year was $ 109,500. Its net purchases were $ 672,600 and net sales were $ 1,279,800 during the year, prior to the tornado. Down Town Dig used the gross profit method to determine it had $ 218,988 of the inventory on hand the date the tornado hit. What is its historical gross profit percentage?