condition mean min max ZT0-3 11.721841666666668 6.649845 19.495800000000003 ZT4-7 16.17345 16.17345 16.17345 ZT8-11 6.72604 6.72604 6.72604 ZT12-15 12.1291275 9.508405 14.749849999999999 ZT16-19 6.239495 6.239495 6.239495 ZT20-23 7.498735 7.498735 7.498735