condition mean min max ZT0-3 18.556413 18.556413 18.556413 ZT4-7 20.636087500000002 20.636087500000002 20.636087500000002 ZT8-11 22.9361305 22.9361305 22.9361305 ZT12-15 16.1355915 16.1355915 16.1355915 ZT16-19 17.332779000000002 17.332779000000002 17.332779000000002 ZT20-23 18.910187 18.910187 18.910187