condition mean min max ZT0-3 8.44686 8.44686 8.44686 ZT4-7 8.1118235 8.1118235 8.1118235 ZT8-11 8.556386499999999 8.556386499999999 8.556386499999999 ZT12-15 8.150967 8.150967 8.150967 ZT16-19 8.222228000000001 8.222228000000001 8.222228000000001 ZT20-23 9.396227 9.396227 9.396227