Subject wise marks weightage in UPSC in the years 2019,2018,2017 and 2016 respectively include:

1. Indian Economy-14%, 16%, 8%, 8%
2. Current Affairs-22%, 28%, 34%, 27%
3. History, Modern India, Indian National Movements-17%, 15%, 14%, 15%
4. Geography- 14%, 8%, 7%, 7%
5. Indian Polity- 15%, 13%, 22%, 7%
6. Science & Technology-7%, 7%, 4%, 8%
7. Environment- 11%, 13%, 11%, 18%

I hope this gives you an idea about the marks weightage of different subjects in UPSC.