condition mean min max ZT0-3 5.428663333333334 5.090310000000001 5.67357 ZT4-7 4.152185 4.152185 4.152185 ZT8-11 6.66205 6.66205 6.66205 ZT12-15 9.61191 9.52889 9.69493 ZT16-19 10.383645000000001 10.383645000000001 10.383645000000001 ZT20-23 8.792349999999999 8.792349999999999 8.792349999999999