condition mean min max ZT0-3 1.5291788333333334 0.5110764999999999 2.341935 ZT4-7 2.529445 2.529445 2.529445 ZT8-11 9.155999999999999 9.155999999999999 9.155999999999999 ZT12-15 2.679875 2.258375 3.101375 ZT16-19 3.729075 3.729075 3.729075 ZT20-23 3.27334 3.27334 3.27334