Done with first four levels of CT Art again.

Level 10: 98%
Level 20: 92%
Level 30: 79%
Level 40: 73%

I was coasting at around 75% on level 40 until the last 50 problems. I perhaps went through them too quickly. I'm not sure whether I will continue to go all the way through CT Art again or whether I'm going to start another pass through the first four levels. The combinations at level 40 are probably too difficult to expect myself to be able to see them instantly, but level 10-30 might be that easy, and it's good to get faster at level 40. Not too sure about using level 50+ this way. Some of the problems are rather tough.

Those results are still fairly weak.