condition mean min max ZT0-3 24.528177 24.528177 24.528177 ZT4-7 21.972135 21.972135 21.972135 ZT8-11 23.902366 23.902366 23.902366 ZT12-15 28.668512999999997 28.668512999999997 28.668512999999997 ZT16-19 24.743233500000002 24.743233500000002 24.743233500000002 ZT20-23 28.081522 28.081522 28.081522