condition mean min max ZT0-3 3.6214313435000003 2.78850474 4.454357947 ZT4-7 6.9707653655 6.559985789500001 7.3815449415000005 ZT8-11 7.56255609975 6.6672340949999995 8.4578781045 ZT12-15 9.3618811185 8.2188719565 10.5048902805 ZT16-19 9.36661537725 8.504793288 10.2284374665 ZT20-23 5.4640436999999995 4.0361723805 6.8919150195