condition mean min max ZT0-3 15.649703 15.649703 15.649703 ZT4-7 18.774116 18.774116 18.774116 ZT8-11 18.6113565 18.6113565 18.6113565 ZT12-15 17.109407 17.109407 17.109407 ZT16-19 16.079908 16.079908 16.079908 ZT20-23 15.462342 15.462342 15.462342