So... I think that the interference level shows the periodic bursts of WiFi energy on a given channel, whereas noise shows the average noise floor over time from both wifi and non-wifi sources.
Based on your photo, I'm thinking that channel 3,4 or 12,13 (if available in your region) would be the best channels to try to operate this AP on. Things are looking pretty noisy though across the board! I'd also make sure that you're using just a 20MHz channel width, and not 40MHz.
Most 2.4GHz WiFi AP's and routers by factory default or by automatic setting use 1, 6, 11... so you can sometimes see better performance by setting up your AP in the valleys between 1, 6, and 11.