Hi nikolina,
I had the same problem in 2017, I realized I did not read enough and I was so upset that I set my target at 20 books for 2018. In 2018 not only I managed it, I read a lot more! So for 2019 my target was 30 books, and I did it. This year I set my goal at 30 books again, 'cause I'm not confident enough to set a new one :) but who knows, I'm not going to stop if I reach the number I set before 31st of december...
RE: 2020. Reading Challenge