condition mean min max ZT0-3 6.91803063 3.7652167199999997 10.07084454 ZT4-7 7.76276580075 5.548383123 9.9771484785 ZT8-11 12.1192740175 10.79564126 13.442906775 ZT12-15 17.128812085 13.800726515000001 20.456897655 ZT16-19 14.2799172725 13.400833075000001 15.15900147 ZT20-23 13.0729904325 13.006984305 13.138996559999999