condition mean min max ZT0-3 24.72565 24.72565 24.72565 ZT4-7 12.350449999999999 12.350449999999999 12.350449999999999 ZT8-11 15.993949999999998 15.993949999999998 15.993949999999998 ZT12-15 21.5313 21.5313 21.5313 ZT16-19 29.625700000000002 29.625700000000002 29.625700000000002 ZT20-23 34.01335 34.01335 34.01335