SQL Server 2012 :: How To Choose Max Of Each Groups Formed By Row Number

I have a below table as:

IF OBJECT_ID('tempdb..#Test') IS NOt NULL
DROP TABLe #Test
--===== Create the test table with
create table #Test([Year] float,
Age Int,
)
INSERT INTO #Test
([Year], Age)

[Code]...

I queried below to get additional column

Select *,row_number() over(partition by [Year] order by Age) as RN from #Test as

YearAgeRN
2014301
2014312
2014323
2015251
2015262
2015273
2015284
2015295

i want one more addtional column (Desired Output) with max of RN in each group as below"

YearAgeRNDesired output
20152515
20152625
20152735
20152845
20152955
20143013
20143123
20143233