condition mean min max ZT0-3 3.3633100000000002 3.3633100000000002 3.3633100000000002 ZT4-7 2.404125 2.404125 2.404125 ZT8-11 2.861735 2.861735 2.861735 ZT12-15 2.51124 2.51124 2.51124 ZT16-19 3.05974 3.05974 3.05974 ZT20-23 2.8985149999999997 2.8985149999999997 2.8985149999999997