In terms of growth, it is 200- 100= 100 this year and 300-200= 100 next year and the year after.

However, if the growth rate is (200-100)/100 =100% this year and (300-200)/200=50% next year and the year after.

If the growth rate remains unchanged, it should be 100 this year, 200 next year and 400 the year after.