condition mean min max ZT0-3 11.886481 11.886481 11.886481 ZT4-7 10.3440325 10.3440325 10.3440325 ZT8-11 11.081236 11.081236 11.081236 ZT12-15 12.8353915 12.8353915 12.8353915 ZT16-19 10.6738495 10.6738495 10.6738495 ZT20-23 11.5382385 11.5382385 11.5382385