condition mean min max ZT0-3 15.77135 15.77135 15.77135 ZT4-7 12.94965 12.94965 12.94965 ZT8-11 15.21 15.21 15.21 ZT12-15 13.94185 13.94185 13.94185 ZT16-19 15.66235 15.66235 15.66235 ZT20-23 14.5948 14.5948 14.5948