condition mean min max ZT0-3 2.898815 2.40437 3.3932599999999997 ZT4-7 3.2393 3.2393 3.2393 ZT8-11 6.024699999999999 6.024699999999999 6.024699999999999 ZT12-15 0 0 0 ZT16-19 6.54452 6.54452 6.54452 ZT20-23 4.47502 4.47502 4.47502