How to find attrition rate over time to find migrants stock?

Question

initial migrant stock in 1991 = 20000

final migrant stock in 1996 = 57000

flow in 1991 = 9000

flow in 1992 = 13000

flow in 1993 = 3400

flow in 1994 = 6000

flow in 1995 = 7000

flows in 1996 = 13000

now how to find attrition rate as well as migrant stocks for each year from 1992 to 1995?

Answer 1

I'm not sure what you mean by this question.