condition mean min max ZT0-3 0.3616566666666667 0.0 1.08497 ZT4-7 0.0 0.0 0.0 ZT8-11 2.23247 2.23247 2.23247 ZT12-15 1.116995 0.0 2.23399 ZT16-19 1.08224 1.08224 1.08224 ZT20-23 1.176845 1.176845 1.176845