condition mean min max ZT0-3 6.33911 6.33911 6.33911 ZT4-7 2.473988 2.473988 2.473988 ZT8-11 5.79868 5.79868 5.79868 ZT12-15 4.423769999999999 4.423769999999999 4.423769999999999 ZT16-19 12.02565 12.02565 12.02565 ZT20-23 11.2767 11.2767 11.2767