condition mean min max ZT0-3 1.2546916666666668 1.1615950000000002 1.38238 ZT4-7 2.13651 2.13651 2.13651 ZT8-11 2.08596 2.08596 2.08596 ZT12-15 5.4775100000000005 5.293195 5.661825 ZT16-19 3.33357 3.33357 3.33357 ZT20-23 2.5342599999999997 2.5342599999999997 2.5342599999999997