which line below is grammatically correct?

I've made a chart and this line goes next to it.

population growth for each decade (for every hundred thousand)

population growth of each decade (for every hundred thousand)

population growth in each decade (for every hundred thousand)

the (for every hundred thousand) means the number 700 on the chart is in fact 70,000,000. Is there any way to improve the wording of it? Please help!!