The common ratio for social users is 1.62 per year what is the percent change?

Common ratio means the multiplier applied to a previous year to get the next year's value.
For example, production was 1000 units this year, the common ratio is 1.62, so next year production is 1.62*1000=1620, with an increase of 620 units over preceding year of 1000. 
So the percentage change is 620/1000 = 0.62 = 62%.