condition mean min max ZT0-3 360.0388889 360.0388889 360.0388889 ZT4-7 203.24222220000001 203.24222220000001 203.24222220000001 ZT8-11 175.33777776666668 175.33777776666668 175.33777776666668 ZT12-15 136.24222221 136.24222221 136.24222221 ZT16-19 223.37222219999998 223.37222219999998 223.37222219999998 ZT20-23 136.07444443333333 136.07444443333333 136.07444443333333