condition mean min max ZT0-3 5.6800625 5.63884 5.721285 ZT4-7 8.883605 8.883605 8.883605 ZT8-11 11.621500000000001 11.621500000000001 11.621500000000001 ZT12-15 0 0 0 ZT16-19 16.59065 16.59065 16.59065 ZT20-23 12.444500000000001 12.444500000000001 12.444500000000001