condition mean min max ZT0-3 20.503683333333335 13.5762 29.09045 ZT4-7 12.5891 12.5891 12.5891 ZT8-11 9.544425 9.544425 9.544425 ZT12-15 14.927975 12.126100000000001 17.72985 ZT16-19 20.862450000000003 20.862450000000003 20.862450000000003 ZT20-23 26.67265 26.67265 26.67265