condition mean min max ZT0-3 6.867845 6.253970000000001 7.481719999999999 ZT4-7 7.699205000000001 7.699205000000001 7.699205000000001 ZT8-11 16.347450000000002 16.347450000000002 16.347450000000002 ZT12-15 0 0 0 ZT16-19 14.4785 14.4785 14.4785 ZT20-23 12.2349 12.2349 12.2349