Rename "Subtotal" to "Subvalue" in Pivot Tables

Description

Pivot Table offers the possibility to show aggregated values by group. For example, if I want to show total sum of sales, I can also show the subtotal sales per category, department etc. In this case a total sum is labeled "Total (Sum)", and the subtotals are labeled "Subtotal". This can also be done with other aggregation functions, such as average. In this case the label for the line aggregating the entire table is "Total (Average)" and the label for a subgroup is "Subtotal". Requesting to rename this to "Subvalue (Average)" (with the aggregated function in brackets).