condition mean min max ZT0-3 41.110725 39.10655 43.1149 ZT4-7 38.6593 38.6593 38.6593 ZT8-11 47.416399999999996 47.416399999999996 47.416399999999996 ZT12-15 0 0 0 ZT16-19 55.265100000000004 55.265100000000004 55.265100000000004 ZT20-23 51.93135 51.93135 51.93135