condition mean min max ZT0-3 9.045181 9.045181 9.045181 ZT4-7 9.058641 9.058641 9.058641 ZT8-11 7.950886 7.950886 7.950886 ZT12-15 10.525631 10.525631 10.525631 ZT16-19 8.374936 8.374936 8.374936 ZT20-23 9.7839095 9.7839095 9.7839095