condition mean min max ZT0-3 5.1000000000000005 5.1000000000000005 5.1000000000000005 ZT4-7 7.6 7.6 7.6 ZT8-11 20.55 20.55 20.55 ZT12-15 35.3 35.3 35.3 ZT16-19 21.5 21.5 21.5 ZT20-23 18.75 18.75 18.75