Bookstore sales rose 9.7% in 2001, to $17.4 billion, according to preliminary estimates from the U.S. Census Bureau. The increase, which matched the gain posted in 2000, was nearly triple that of the entire retail segment, which had a 3.4% sales increase for the year. December sales rose 9.6%, to $2.29 billion, the largest monthly increase since bookstore sales began to slow after September 11. Sales for all of retail increased 3.2% in December.