condition mean min max ZT0-3 8.024675 7.770815 8.278535 ZT4-7 9.994035 9.994035 9.994035 ZT8-11 10.179780000000001 10.179780000000001 10.179780000000001 ZT12-15 0 0 0 ZT16-19 12.081949999999999 12.081949999999999 12.081949999999999 ZT20-23 9.104780000000002 9.104780000000002 9.104780000000002