Complex sentence: It was published by Viking Press in 1967, during her freshman year at the University of Tulsa; the book has sold more than 14 million copies in print and still sells more than 500,000 a year.
Split into simpler sentences: It was published by Viking Press in 1967, during her freshman year at the University of Tulsa. Since then, the book has sold more than 14 million copies and still sells more than 500,000 a year.