condition mean min max ZT0-3 8.5622375 8.2277 8.896775 ZT4-7 7.466925 7.466925 7.466925 ZT8-11 7.40153 7.40153 7.40153 ZT12-15 0 0 0 ZT16-19 10.305735 10.305735 10.305735 ZT20-23 9.938695 9.938695 9.938695