condition mean min max ZT0-3 7.999459999999999 7.999459999999999 7.999459999999999 ZT4-7 6.482425 6.482425 6.482425 ZT8-11 7.855219999999999 7.855219999999999 7.855219999999999 ZT12-15 10.725455 10.725455 10.725455 ZT16-19 9.44981 9.44981 9.44981 ZT20-23 8.202175 8.202175 8.202175