condition mean min max ZT0-3 51.3 51.3 51.3 ZT4-7 66.5 66.5 66.5 ZT8-11 39.9 39.9 39.9 ZT12-15 45.7 45.7 45.7 ZT16-19 11.299999999999999 11.299999999999999 11.299999999999999 ZT20-23 68.4 68.4 68.4