condition mean min max ZT0-3 6.12967186375 5.559617557999999 6.6997261695 ZT4-7 5.186668196 4.297344367000001 6.075992025 ZT8-11 4.7105914997500005 4.596664247 4.8245187525 ZT12-15 2.7928150755 2.722047838 2.863582313 ZT16-19 1.6436904879999998 1.4629516269999998 1.824429349 ZT20-23 1.9709290785 0.9248141515 3.0170440055