condition mean min max ZT0-3 216.942792 216.942792 216.942792 ZT4-7 280.074677 280.074677 280.074677 ZT8-11 320.900804 320.900804 320.900804 ZT12-15 330.023685 330.023685 330.023685 ZT16-19 270.5838175 270.5838175 270.5838175 ZT20-23 188.5906545 188.5906545 188.5906545