Task: Question Generation
Input (English): Passage: Birth registration of Bahrain is available from 1976, death registration started in 1990. Between 1976 and 2011 the number of baby births roughly doubled but the birth rate of babies decreased from 32 to 13 per 1,000. The death rate of Bahrain  is among the lowest in the world.
Output (English): How many year time span did births roughly double in Bahrain?