condition mean min max ZT0-3 41.764987 41.764987 41.764987 ZT4-7 31.100288499999998 31.100288499999998 31.100288499999998 ZT8-11 28.220284999999997 28.220284999999997 28.220284999999997 ZT12-15 24.928112499999997 24.928112499999997 24.928112499999997 ZT16-19 23.4922695 23.4922695 23.4922695 ZT20-23 27.793293 27.793293 27.793293