condition mean min max ZT0-3 2.9195575465 2.112970959 3.726144134 ZT4-7 5.86582562475 4.5986207885 7.133030461000001 ZT8-11 10.916766589249999 8.7994283525 13.034104826 ZT12-15 15.157360947499999 14.265677455 16.04904444 ZT16-19 11.862448220000001 11.769332015 11.955564425 ZT20-23 10.842326752249999 9.5658432495 12.118810255