condition mean min max ZT0-3 8.42098 8.42098 8.42098 ZT4-7 6.18599 6.18599 6.18599 ZT8-11 2.1094600000000003 2.1094600000000003 2.1094600000000003 ZT12-15 3.2911 3.2911 3.2911 ZT16-19 15.0484 15.0484 15.0484 ZT20-23 11.19185 11.19185 11.19185