condition mean min max ZT0-3 18.97135 18.97135 18.97135 ZT4-7 18.013091666666668 18.013091666666668 18.013091666666668 ZT8-11 18.27365 18.27365 18.27365 ZT12-15 19.62905 19.62905 19.62905 ZT16-19 18.546775 18.546775 18.546775 ZT20-23 18.1613 18.1613 18.1613