Unfollow Ratio against Time

Hi guys, I have been following/liking users for the past 2 years.

My follow ratio remains the same (about 50%). Although I notice that my stats for new followers per day keep decreasing, meaning that my unfollow ratio goes up with time.

Have anyone experienced this?

I used to get 500-600 new follows each day in the beginning. Now I can hardly make half of it, even though I have the same follow-back ratio of 50%.

I believe this has to do with time.

Old followers, once note that have been unfollowed, unfollow the account. And this number increases with time.

I suppose there will be a day that new followers and unfollows will be equal and my account will reach it’s peak followers.

Does this make sense?

For example:
day 1: 1000 follows = 500 new followers - 10% unfollows = 450
day 2: 1000 follows = 500 new followers - 10% unfollows - X% unfollows from past = 450 - X%