condition mean min max ZT0-3 5.1914 5.1914 5.1914 ZT4-7 4.776505 4.776505 4.776505 ZT8-11 4.53073 4.53073 4.53073 ZT12-15 5.51951 5.51951 5.51951 ZT16-19 7.334375 7.334375 7.334375 ZT20-23 5.96524 5.96524 5.96524