Question: This year, the percentage of our female users is 5%, we estimate this percentage will be 7%, 9%, 11%, 13% for the following years.

Can we say "This year, the percentage of our female users is 5%, we estimate this percentage will increment 2% every year."?

How could I make it clear that it is not `5%*(1+2%)`, `5%*(1+2%)*(1+2%)`, `5%*(1+2%)*(1+2%)*(1+2%)`, etc.?

And what if one wants to say the estimation is `5%*(1+2%)`, `5%*(1+2%)*(1+2%)`, `5%*(1+2%)*(1+2%)*(1+2%)`, etc.?

Answer: 
One way to say it is

* We estimate that this will increase by two percentage points every year.

Considering that you established, in the previous sentence, what you are talking about, the word "this" would be clear without the word "percentage" after it. However, for clarity, you need the full phrase "[percentage points](https://en.wiktionary.org/wiki/percentage_point#English)" --- mere "points" is too vague; listeners won't know what you mean.

To express an absolute difference between percentages, state it in percentage points. If you say "percent", that refers to the factor difference. The web page I linked to above explains this, too.
To avoid the ambiguity you refer to, I would say:

> 
> "This year, the percentage of our female users is 5%, and we estimate that this percentage will increase 2% every year, i.e. 5%, 7%, 9%, etc."
> 
> 
> 

If in fact you estimate 5%, 5 × 1.02%, 5 × 1.02 × 1.02%, 5 × 1.02 × 1.02 × 1.02%, etc. then I would say:

> 
> "This year, the percentage of our female users is 5%, and we estimate that this percentage will increase 2% exponentially every year, i.e. 5%, 5.1%, 5.202%, etc."
> 
> 
> 

(In the first case, you could say "... will increase 2% additively every year..." but the word "additively" is a bit extra, i.e. unnecessary.)