condition mean min max ZT0-3 6.92295 6.599265000000001 7.2466349999999995 ZT4-7 7.800345 7.800345 7.800345 ZT8-11 7.818065 7.818065 7.818065 ZT12-15 0 0 0 ZT16-19 8.691324999999999 8.691324999999999 8.691324999999999 ZT20-23 6.70501 6.70501 6.70501