Data:

label: 'Year',  'Sales',    null, 'Expenses',     null
 role: domain,   data, certainty,     data,  certainty
       '2004',   1000,     false,      400,      true
       '2005',   1170,      true,      460,      true
       '2006',    660,      true,     1120,      false
       '2007',   1030,      true,      540,      false

In this chart, the 'Sales' series has one uncertain segment, the first segment, because of the uncertain boundary point in the first row. The 'Expenses' series has two uncertain segments, specified by the uncertainty of the last two points in the fifth column.