condition mean min max ZT0-3 21.7389 21.7389 21.7389 ZT4-7 18.93165 18.93165 18.93165 ZT8-11 18.2382 18.2382 18.2382 ZT12-15 22.07235 22.07235 22.07235 ZT16-19 26.4815 26.4815 26.4815 ZT20-23 28.7558 28.7558 28.7558