Issues with reporting percent log space used, between DMV and DBCC

Using SQL Server 2012 SE 11.0.2100, I am getting two different sets of values when querying for log space between the DMV and the DBCC command. 

Querying using the DMV.

select instance_name as DBName, cntr_value as PercentLogUsed from sys.dm_os_performance_counters where counter_name = 'Percent Log Used' and instance_name <> '_Total' and instance_name <> 'mssqlsystemresource' and instance_name <> 'model' order by cntr_value desc

The results that I get from using this DMV are about 10% off from the results that I get when I use dbcc.

DBCC SQLPERF(logspace)

Why is this?