condition mean min max ZT0-3 18.377256 18.377256 18.377256 ZT4-7 17.824872499999998 17.824872499999998 17.824872499999998 ZT8-11 14.7119195 14.7119195 14.7119195 ZT12-15 15.512346999999998 15.512346999999998 15.512346999999998 ZT16-19 14.124924 14.124924 14.124924 ZT20-23 17.7571655 17.7571655 17.7571655