Dixie's solution seems simple, but won't work for dates before 1950.

I've done this that would work for any date between today and 100 years in the past (almost).

And a simple test.

DECLARE @tDatestable(

RSAIDchar(8));

WITH E1(N) AS (

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1

),

E2(N) AS (SELECT 1 FROM E1 a, E1 b)

INSERT @tDates

SELECT RIGHT( '00'+ CAST(ROW_NUMBER() OVER(ORDER BY N) - 1 AS varchar(2)), 2) + '0101'

FROM E2

SELECT RSAID,

CASE WHEN convert(date, RSAID) <= GETDATE() --LEFT( RSAID, 2) <= RIGHT( YEAR(GETDATE()),2)

THEN convert(char(11),convert(date,'20' + RSAID),106)

ELSE convert(char(11),convert(date,'19' + RSAID),106) END

FROM @tDates

ORDER BY 2