condition mean min max ZT0-3 4.19592 3.363765 5.1322849999999995 ZT4-7 3.049625 3.049625 3.049625 ZT8-11 3.19576 3.19576 3.19576 ZT12-15 5.64021 4.12101 7.15941 ZT16-19 4.421815 4.421815 4.421815 ZT20-23 6.5382 6.5382 6.5382