condition mean min max ZT0-3 6.02583 6.02583 6.02583 ZT4-7 5.68298 5.68298 5.68298 ZT8-11 3.95656 3.95656 3.95656 ZT12-15 4.878095 4.878095 4.878095 ZT16-19 5.18968 5.18968 5.18968 ZT20-23 6.49777 6.49777 6.49777