condition mean min max ZT0-3 233.916887 233.916887 233.916887 ZT4-7 504.20955449999997 504.20955449999997 504.20955449999997 ZT8-11 477.2872765 477.2872765 477.2872765 ZT12-15 397.17503 397.17503 397.17503 ZT16-19 342.477148 342.477148 342.477148 ZT20-23 295.3570775 295.3570775 295.3570775