condition mean min max ZT0-3 41.144225 38.6819 43.60655 ZT4-7 16.04985 16.04985 16.04985 ZT8-11 13.991299999999999 13.991299999999999 13.991299999999999 ZT12-15 0 0 0 ZT16-19 31.2444 31.2444 31.2444 ZT20-23 47.09895 47.09895 47.09895