condition mean min max ZT0-3 2.2702150000000003 2.2702150000000003 2.2702150000000003 ZT4-7 2.267755 2.267755 2.267755 ZT8-11 1.967695 1.967695 1.967695 ZT12-15 1.747515 1.747515 1.747515 ZT16-19 2.323735 2.323735 2.323735 ZT20-23 1.8255500000000002 1.8255500000000002 1.8255500000000002