condition mean min max ZT0-3 8.782575 8.782575 8.782575 ZT4-7 8.870442 8.870442 8.870442 ZT8-11 9.378823 9.378823 9.378823 ZT12-15 9.3950695 9.3950695 9.3950695 ZT16-19 9.3428685 9.3428685 9.3428685 ZT20-23 9.1090175 9.1090175 9.1090175