SSRS: Summing Static Rows Defined by Expressions

I am building a report that looks like:

          Last 30 Days     Last 60 Days     Last 90 Days
SLA Met*      1          开发者_开发技巧      3                5 
SLA Missed*   2                4                6 
Total         3                7                11 

The datasource is via FetchXML and only one dataset is being used for the table. I am calculating the static rows, SLA Met and SLA Missed, using the expresion:

=(Count(IIf Condition, 1, Nothing)). 

Any ideas how I would get the total of these two static rows, as they do not belong to a group, not fields that I can easily sum, and are defined by an expression?

Thanks.

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If I clearly understood the problem, the solution would be simple: = (expression) + (expression)

This amount must be in the same table.

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You can create calculated fields with your condition, then use that data to create your total rows. They would then belong to the group and would be easy to sum up.