Staking - ROI annual percentage


I wanted to know is the ROI percentage of staking fixed or and high?
Are the estimates of 5-10 % correct?
Is the ROI with or wihtout transactions fees?

Because I’m staking pretty many times at present(60+ times in the last month), but if I calculate an estimate of my annual rewards over the last month it’s somewhere between 1- 2%.
Can this be accurate, or is my configuration abit of? Or is it not possible to estimate the reward percentage on such a same sample data?:thinking::face_with_monocle: