condition mean min max ZT0-3 14.149999999999999 14.149999999999999 14.149999999999999 ZT4-7 4.3 4.3 4.3 ZT8-11 17.05 17.05 17.05 ZT12-15 11.850000000000001 11.850000000000001 11.850000000000001 ZT16-19 17.85 17.85 17.85 ZT20-23 8.35 8.35 8.35