I add about 1/2 cup of baking soda to every load of laundry. We have pretty hard water. The baking soda softens it so that it is more effective at washing away the detergent. Been doing this for a couple of years and I have noticed that our towels don't lose absorbency like towels we've had in the past.
The average number of children each woman will have over the course of her lifetime is called the Fertility Rate In 2011, the overall global life expectancy for both men and women was
Gross Reproduction Rate (GRR) The average number of daughters that would be born alive to a woman (or group of women) during her lifetime if she passed through her childbearing years conforming to the age-specific fertility rates of a given year.