condition mean min max ZT0-3 6.4073383333333345 4.35599 8.311755000000002 ZT4-7 4.83012 4.83012 4.83012 ZT8-11 5.1741150000000005 5.1741150000000005 5.1741150000000005 ZT12-15 6.22431 6.03495 6.41367 ZT16-19 7.731725 7.731725 7.731725 ZT20-23 11.6902 11.6902 11.6902