condition mean min max ZT0-3 2.5387175 1.7154150000000001 3.3620200000000002 ZT4-7 2.2725750000000002 2.2725750000000002 2.2725750000000002 ZT8-11 4.653725 4.653725 4.653725 ZT12-15 0 0 0 ZT16-19 2.8106850000000003 2.8106850000000003 2.8106850000000003 ZT20-23 0.567565 0.567565 0.567565