Calculating weighted average of percentage values

Question

I have total sales of each year like so:

2018 100$
2019 150$
2020 210$

I am trying to find the weighted moving average(here moving over 2 years for simplicity) of the % growth, which looks something like this : ((current year sales - previous year sales)/ previous year sales) x 100

2018 100$
2019 150$ 50%
2020 210% 40%

So, a regular average of 50 and 40 would be (50+40)/2 = 45%

I need to give the recent years more weightage, hence I want to do the following : (0.25X50) + (0.75X40) = 12.5 + 30 = 42.5% Is the aforementioned method correct way of finding a weighted average of percentage values ?