condition mean min max ZT0-3 17.756625 15.4023 20.110950000000003 ZT4-7 13.9855 13.9855 13.9855 ZT8-11 9.31385 9.31385 9.31385 ZT12-15 0 0 0 ZT16-19 13.3553 13.3553 13.3553 ZT20-23 13.29535 13.29535 13.29535