condition mean min max ZT0-3 15.580296 15.580296 15.580296 ZT4-7 12.7281625 12.7281625 12.7281625 ZT8-11 11.3700645 11.3700645 11.3700645 ZT12-15 13.024518 13.024518 13.024518 ZT16-19 11.543290500000001 11.543290500000001 11.543290500000001 ZT20-23 12.844389 12.844389 12.844389