Date conversion with condition : Please feel free to suggest me to change the title.
I have a hire date column and I want to assign specific Tiers depending on employee work years with the following conditions:

        1-4 years = T1
        5-9 years = T2
        10-15 years = T3
        15+ years = T4

For example, if the hire date is 12/07/2002, the tier should equal T4.
		 
		 10/03/2016 = T1
	     01/18/2010 = T2
		 01/14/2006 = T3
         12/07/2002 = T4
                 
Is there any way to accomplish this?

Your help will be greatly appreciated. 