condition mean min max ZT0-3 6.217280000000001 6.217280000000001 6.217280000000001 ZT4-7 5.30779 5.30779 5.30779 ZT8-11 5.264435000000001 5.264435000000001 5.264435000000001 ZT12-15 5.94794 5.94794 5.94794 ZT16-19 6.06626 6.06626 6.06626 ZT20-23 6.47583 6.47583 6.47583