Please post the link that you mentioned so others can see what you have seen. Thanks.

If you want to generate a million rows of sample data using those ratios, you could do the following. This takes about 1-1/2 seconds to gen a table with a million rows in it.

WITH

cteGenMillionNumbers AS

(

SELECT TOP 1000000

N = ABS(CHECKSUM(NEWID()))%100+1

FROM sys.all_columns ac1

CROSS JOIN sys.all_columns ac2

)

SELECT SomeID= IDENTITY(INT,1,1),

Grade = CASE

WHEN N BETWEEN 1 AND 40 THEN 1

WHEN N BETWEEN 41 AND 65 THEN 2

WHEN N BETWEEN 66 AND 85 THEN 3

WHEN N BETWEEN 86 AND 99 THEN 4

WHEN N = 100 THEN 5

ELSE 0 --will never happen but I do these types of safety checks

END

INTO #MyHead

FROM cteGenMillionNumbers

;