condition mean min max ZT0-3 66.41515 66.41515 66.41515 ZT4-7 40.8776 40.8776 40.8776 ZT8-11 76.74235 76.74235 76.74235 ZT12-15 44.2565 44.2565 44.2565 ZT16-19 83.99835 83.99835 83.99835 ZT20-23 71.23055 71.23055 71.23055