condition mean min max ZT0-3 12.426466666666666 11.587 13.89865 ZT4-7 12.1596 12.1596 12.1596 ZT8-11 13.7344 13.7344 13.7344 ZT12-15 9.04251 8.623655 9.461365 ZT16-19 9.013390000000001 9.013390000000001 9.013390000000001 ZT20-23 9.258275000000001 9.258275000000001 9.258275000000001