Hello everyone! I am a new user here. I'm an undergrad studying in Goa.
I'm working to study and observe a pattern in R&D behavior of manufacturing MSMEs as defined by the govt. There are around 6900 companies and the time considered is 1992 to 2018.

The issue is that all the companies haven't been in existence throughout the time frame, but while downloading the data contains just empty rows for the missing years. When I load the data into Stata, it shows strongly balanced, even though I know it's not.

I can't understand how to work with this unbalanced data.

Any help would be appreciated.
Thank you!