condition mean min max ZT0-3 536.222726 536.222726 536.222726 ZT4-7 366.9677655 366.9677655 366.9677655 ZT8-11 154.196891 154.196891 154.196891 ZT12-15 57.404205499999996 57.404205499999996 57.404205499999996 ZT16-19 197.32239 197.32239 197.32239 ZT20-23 480.4998345 480.4998345 480.4998345