condition mean min max ZT0-3 45.887223 45.887223 45.887223 ZT4-7 37.1952085 37.1952085 37.1952085 ZT8-11 31.808519999999998 31.808519999999998 31.808519999999998 ZT12-15 30.3779745 30.3779745 30.3779745 ZT16-19 19.010241 19.010241 19.010241 ZT20-23 20.673957 20.673957 20.673957