condition mean min max ZT0-3 13.15 13.15 13.15 ZT4-7 7.1 7.1 7.1 ZT8-11 17.85 17.85 17.85 ZT12-15 10.45 10.45 10.45 ZT16-19 11.299999999999999 11.299999999999999 11.299999999999999 ZT20-23 4.45 4.45 4.45