condition mean min max ZT0-3 21.031482 21.031482 21.031482 ZT4-7 24.0279435 24.0279435 24.0279435 ZT8-11 21.3455485 21.3455485 21.3455485 ZT12-15 25.1852035 25.1852035 25.1852035 ZT16-19 22.979953000000002 22.979953000000002 22.979953000000002 ZT20-23 19.30002 19.30002 19.30002