condition mean min max ZT0-3 10.586879 10.586879 10.586879 ZT4-7 11.5606595 11.5606595 11.5606595 ZT8-11 13.838680499999999 13.838680499999999 13.838680499999999 ZT12-15 12.509015 12.509015 12.509015 ZT16-19 13.340717999999999 13.340717999999999 13.340717999999999 ZT20-23 13.903134999999999 13.903134999999999 13.903134999999999