condition mean min max ZT0-3 818.938031 818.938031 818.938031 ZT4-7 638.78321 638.78321 638.78321 ZT8-11 599.892471 599.892471 599.892471 ZT12-15 710.6355185 710.6355185 710.6355185 ZT16-19 776.014234 776.014234 776.014234 ZT20-23 825.6843615 825.6843615 825.6843615