Task: Question Understanding
Input (English): Passage: Between 2000 and 2009, school enrollment declined by 121,000 students, and the number of teachers increased by 15,000. The student:teacher ratio was the eighth lowest in the country, 13:1. At $16,000, its per student spending was the nation's highest.
Question: How many years did it take for school enrollment to decline by 121,000 students?
Output (English): number