condition mean min max ZT0-3 18.037526645 17.26963004 18.80542325 ZT4-7 16.062582962500002 15.35829652 16.766869405 ZT8-11 14.91659912 14.399111815000001 15.434086425 ZT12-15 23.49592421 22.985896175 24.005952245 ZT16-19 28.0181417125 26.921365955 29.11491747 ZT20-23 24.982446834999998 24.699538835 25.265354835