How can you verify SP2 /CU13 is applied on SQL Server 2008R2

Run the below script:
Select serverproperty('productlevel') as 'productlevel',
serverproperty('ProductVersion') as 'ProductVersion'

	ProductLevel	ProductVersion
After Applying SP2	SP2	10.50.4000.0
After Applying SP2 and CU13	SP2	10.50.4319.0