condition mean min max ZT0-3 42.793831 42.793831 42.793831 ZT4-7 33.1951745 33.1951745 33.1951745 ZT8-11 29.7038905 29.7038905 29.7038905 ZT12-15 30.5347995 30.5347995 30.5347995 ZT16-19 24.56669 24.56669 24.56669 ZT20-23 28.130437999999998 28.130437999999998 28.130437999999998