condition mean min max ZT0-3 65.613075 58.8012 72.42495 ZT4-7 64.2883 64.2883 64.2883 ZT8-11 48.6872 48.6872 48.6872 ZT12-15 0 0 0 ZT16-19 35.35725 35.35725 35.35725 ZT20-23 48.449 48.449 48.449