Hello! I have data on the year that employees joined a company, startyear. In order to figure out their tenure, I want to generate a new variable Tenure that is the current year minus the year they started.

I have tried doing:
gen Tenure = 2020 - startyear

However, the results are really funky (For example, it is giving me a max value of 2021) so I don't think that is correct. Am I missing something?