condition mean min max ZT0-3 17.3562789 15.10331986 19.60923794 ZT4-7 60.783816172499996 43.11604108 78.45159126499999 ZT8-11 119.901770105 82.78381976 157.01972045 ZT12-15 88.6706916025 54.158354115 123.18302908999999 ZT16-19 39.1243672625 35.91632087 42.332413654999996 ZT20-23 14.01742505975 6.1473927595 21.88745736