condition mean min max ZT0-3 2.65274243225 1.8577502154999999 3.447734649 ZT4-7 7.865881537833333 4.787107035666667 10.94465604 ZT8-11 10.701857529 9.445455992 11.958259066 ZT12-15 9.618923780166668 8.784245619333333 10.453601941 ZT16-19 11.143417999499999 10.247627739 12.039208259999999 ZT20-23 10.237120272 9.996714476333334 10.477526067666666