Nested Aggregation for Averages

[MassicotPSCU]

Is there any way to just take this number in the totals row and put it in a KPI card?  The "Sales and Sales per hour" field is being derived from the following expression. 

=if(IsNull(avg([Sales / Hour])),(count([Sale ID])/sum([Hours])),avg([Sales / Hour]))

Once I have the values, I use the total row to get the average of all the numbers for the given months. When I try to just copy paste this expression into a KPI card, I get a different result. Is there any way to include the average of all months in my expression?

[Chanty4u]

May b try this 

=avg({<Month= >}[Sales /hour])