condition mean min max ZT0-3 9.104134 9.104134 9.104134 ZT4-7 9.977256 9.977256 9.977256 ZT8-11 9.607642 9.607642 9.607642 ZT12-15 9.988364 9.988364 9.988364 ZT16-19 9.607642 9.607642 9.607642 ZT20-23 9.535717 9.535717 9.535717