condition mean min max ZT0-3 52.137433 52.137433 52.137433 ZT4-7 48.327786 48.327786 48.327786 ZT8-11 54.688322 54.688322 54.688322 ZT12-15 53.472091 53.472091 53.472091 ZT16-19 66.968763 66.968763 66.968763 ZT20-23 60.6894485 60.6894485 60.6894485