condition mean min max ZT0-3 14.386199999999999 14.386199999999999 14.386199999999999 ZT4-7 8.174145 8.174145 8.174145 ZT8-11 4.4086099999999995 4.4086099999999995 4.4086099999999995 ZT12-15 8.59239 8.59239 8.59239 ZT16-19 21.36475 21.36475 21.36475 ZT20-23 28.06035 28.06035 28.06035