condition mean min max ZT0-3 294.519818 294.519818 294.519818 ZT4-7 280.1115585 280.1115585 280.1115585 ZT8-11 294.7426005 294.7426005 294.7426005 ZT12-15 335.37434099999996 335.37434099999996 335.37434099999996 ZT16-19 305.890894 305.890894 305.890894 ZT20-23 388.648065 388.648065 388.648065