several same environment variables in my path

Hi, I noticed accidently today on my PATH and discovered that I have several variables for different sql versions. I can understand this as I have upgraded from 2008, to 2012 then 2014. Here are the list of variables

C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;
C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;
C:\Program Files\Microsoft SQL Server\120\DTS\Binn\;
C:\Program Files (x86)\Microsoft SQL Server\120\DTS\Binn\;
C:\Program Files\Microsoft SQL Server\120\Tools\Binn\;
C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\110\Tools\Binn\;

C:\Program Files (x86)\Microsoft SQL Server\120\Tools\Binn\;
C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\;

C:\Program Files (x86)\Microsoft SQL Server\120\Tools\Binn\ManagementStudio\;
C:\Program Files (x86)\Microsoft SQL Server\110\Tools\Binn\ManagementStudio\;

Can I delete all variables related to older versions safely without any issue

Thanks