Country-pop singer Taylor Swift has said that she still suffers from “anxiety” over her album sales.

Speaking to Billboard.com, the 20-year-old multi-platinum artist revealed that she regularly worries about how many copies her records are selling and tries to “predict” her projected sales figures:

“I have a lot of anxiety about things on certain days. It’s a five-minute conversation about if a number really defines this piece of art that I’ve created and what that means.”

She added: “Then I realise that I can’t predict what [the sales figure] is going to be, and I sit there and say something to myself like, ‘Well, you’re happy today. Enjoy this and be proud of the music that you’ve made’.”

Check out Swift’s performance of ‘Love Story’ on David Letterman below: