condition mean min max ZT0-3 6.06553 6.06553 6.06553 ZT4-7 9.198725 9.198725 9.198725 ZT8-11 6.01538 6.01538 6.01538 ZT12-15 7.04838 7.04838 7.04838 ZT16-19 4.117145000000001 4.117145000000001 4.117145000000001 ZT20-23 6.07364 6.07364 6.07364