condition mean min max ZT0-3 11.850000000000001 11.850000000000001 11.850000000000001 ZT4-7 17.6 17.6 17.6 ZT8-11 5.8 5.8 5.8 ZT12-15 12.55 12.55 12.55 ZT16-19 9.45 9.45 9.45 ZT20-23 1.6 1.6 1.6