condition mean min max ZT0-3 11.858965 4.734055 17.51195 ZT4-7 12.702134999999998 12.702134999999998 12.702134999999998 ZT8-11 4.354675 4.354675 4.354675 ZT12-15 7.1731575 4.719815 9.6265 ZT16-19 4.206035 4.206035 4.206035 ZT20-23 18.63295 18.63295 18.63295