condition mean min max ZT0-3 21.043100000000003 21.043100000000003 21.043100000000003 ZT4-7 18.6834 18.6834 18.6834 ZT8-11 20.639049999999997 20.639049999999997 20.639049999999997 ZT12-15 25.02525 25.02525 25.02525 ZT16-19 31.5169 31.5169 31.5169 ZT20-23 24.7568 24.7568 24.7568