condition mean min max ZT0-3 3.580955 3.580955 3.580955 ZT4-7 2.445855 2.445855 2.445855 ZT8-11 2.01098 2.01098 2.01098 ZT12-15 2.21195 2.21195 2.21195 ZT16-19 3.380335 3.380335 3.380335 ZT20-23 3.2683999999999997 3.2683999999999997 3.2683999999999997