KQL queries to get total storage account used space in percentage

I am writing KQL queries to setup alerting mechanism in our environment. However we got blocked for few alerts.

I need to get total used capacity of storage account in percentage, with below query I am able to get total used Capacity but not in percentage:

     AzureMetrics
     |   where ResourceProvider  == "MICROSOFT.STORAGE"
     |   where MetricName        == "UsedCapacity"

I tried to reproduce the same in my environment and below is the result

need to get total used capacity of storage account in percentage, with below query i am able to get total used Capacity but not in percentage

You can use below KQL query to get the output in percentage.

AzureMetrics  
| where ResourceProvider == "MICROSOFT.STORAGE"  
| summarize Totalvalue = sum(Total) by MetricName| as T  
| extend Percentage = round(100.0 * Totalvaule / toscalar(T | summarize sum(Totalvalue)), 2)

Output