Graph About Optimist Yachting

On the first day I went optimist yachting, I thought I would be a 4/10 because it was a long time since I had done it.
On Tuesday and Wednesday I thought I would be a 6/10 because I still was very good.
For Thursday I thought I would be a 7/10 because I was getting better but, I still was very good.
On the last day I went optimist yachting I wanted to try to sail by myself, so I did and thought I would be a 9/10.