Hey, the higher lvl maps can be rahter much easier than the lower ones. For example 161 and 172 are way easy. I would suggest switching the lvl of the easier maps to harder. For example Lv.72 fits very good as a high lvl. Some lvls i think need to switch difficulity:
161, 126, 172, 121 - lower
72, 76(escaping chernobyl), 111, 115, 66, - higher