condition mean min max ZT0-3 4.438616666666666 1.568865 6.4507650000000005 ZT4-7 1.77803 1.77803 1.77803 ZT8-11 0.8565265 0.8565265 0.8565265 ZT12-15 1.1146337499999999 1.000078 1.2291895 ZT16-19 1.4123299999999999 1.4123299999999999 1.4123299999999999 ZT20-23 4.227335 4.227335 4.227335