condition mean min max ZT0-3 30.35 30.35 30.35 ZT4-7 11.8 11.8 11.8 ZT8-11 6.15 6.15 6.15 ZT12-15 15.450000000000001 15.450000000000001 15.450000000000001 ZT16-19 9.1 9.1 9.1 ZT20-23 12.9 12.9 12.9