condition mean min max ZT0-3 13.450000000000001 13.450000000000001 13.450000000000001 ZT4-7 40.5 40.5 40.5 ZT8-11 5.5 5.5 5.5 ZT12-15 22.7 22.7 22.7 ZT16-19 11.299999999999999 11.299999999999999 11.299999999999999 ZT20-23 27.45 27.45 27.45