condition mean min max ZT0-3 222.527721 222.527721 222.527721 ZT4-7 233.8484315 233.8484315 233.8484315 ZT8-11 249.23573349999998 249.23573349999998 249.23573349999998 ZT12-15 261.69688799999994 261.69688799999994 261.69688799999994 ZT16-19 205.579117 205.579117 205.579117 ZT20-23 199.29798699999998 199.29798699999998 199.29798699999998