condition mean min max ZT0-3 3.97201 3.97201 3.97201 ZT4-7 3.2359099999999996 3.2359099999999996 3.2359099999999996 ZT8-11 3.89386 3.89386 3.89386 ZT12-15 5.020945 5.020945 5.020945 ZT16-19 5.947699999999999 5.947699999999999 5.947699999999999 ZT20-23 4.583625 4.583625 4.583625