condition mean min max ZT0-3 26.1894 23.383 28.9958 ZT4-7 10.061625 10.061625 10.061625 ZT8-11 12.1856 12.1856 12.1856 ZT12-15 0 0 0 ZT16-19 15.54025 15.54025 15.54025 ZT20-23 21.9316 21.9316 21.9316