condition mean min max ZT0-3 2.35 2.35 2.35 ZT4-7 2.8 2.8 2.8 ZT8-11 18.450000000000003 18.450000000000003 18.450000000000003 ZT12-15 2.7 2.7 2.7 ZT16-19 32.75 32.75 32.75 ZT20-23 14.1 14.1 14.1