SQL Server 2019

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CREATE TABLE #TEST 
(
    MONTH INT,
    TYPE VARCHAR(10),
    TENURE INT,
    NUMERADOR INT,
    DENOMINADOR INT
)

INSERT INTO #TEST
VALUES  (1, 'TYPE1', 35, 320, 60),
        (1, 'TYPE1', 96, 511, 75),
        (1, 'TYPE2', 23, 400, 72),
        (1, 'TYPE2', 102, 500, 84); 
4 rows affected

SELECT
   MONTH
  ,TYPE
  ,SUM(                            NUMERADOR    ) / CONVERT(DECIMAL(10,4), SUM(                            DENOMINADOR    )) [CALCULATION]
  ,SUM(CASE WHEN TENURE <  90 THEN NUMERADOR END) / CONVERT(DECIMAL(10,4), SUM(CASE WHEN TENURE <  90 THEN DENOMINADOR END)) [NO_TENURE]
  ,SUM(CASE WHEN TENURE >= 90 THEN NUMERADOR END) / CONVERT(DECIMAL(10,4), SUM(CASE WHEN TENURE >= 90 THEN DENOMINADOR END)) [TENURE]
FROM
  #TEST
GROUP BY
   MONTH,
   TYPE


MONTH
TYPE
CALCULATION
NO_TENURE
TENURE


1
TYPE1
6.15555555555
5.33333333333
6.81333333333

1
TYPE2
5.76923076923
5.55555555555
5.95238095238


Warning: Null value is eliminated by an aggregate or other SET operation.


WITH
  NORMALISED_RESULT AS
(
  SELECT
    MONTH,
    TYPE,
    IS_TENURED,
    SUM(NUMERADOR) / CONVERT(DECIMAL(10,4), SUM(DENOMINADOR)) AS CALCULATION
  FROM
    #TEST
  CROSS APPLY
  (
    SELECT
      CASE WHEN TENURE <  90 THEN 0
           WHEN TENURE >= 90 THEN 1
                             ELSE -1 END AS IS_TENURED
  )
    AS TENURE_CHECK
  GROUP BY
    GROUPING SETS(
      (MONTH, TYPE, IS_TENURED),
      (MONTH, TYPE)
    )
)

-- This next part just pivots the normalised results
-- It can be skipped if three rows of normalised results is acceptable.

SELECT
  MONTH,
  TYPE,
  MAX(CASE WHEN IS_TENURED IS NULL THEN CALCULATION END) AS CALCULATION,
  MAX(CASE WHEN IS_TENURED = 0     THEN CALCULATION END) AS NO_TENURE,
  MAX(CASE WHEN IS_TENURED = 1     THEN CALCULATION END) AS TENURE
FROM
  NORMALISED_RESULT
GROUP BY
  MONTH,
  TYPE


MONTH
TYPE
CALCULATION
NO_TENURE
TENURE


1
TYPE1
6.15555555555
5.33333333333
6.81333333333

1
TYPE2
5.76923076923
5.55555555555
5.95238095238


Warning: Null value is eliminated by an aggregate or other SET operation.


SELECT
    MONTH,
    TYPE,
    IS_TENURED,
    SUM(NUMERADOR) / CONVERT(DECIMAL(10,4), SUM(DENOMINADOR)) AS CALCULATION
  FROM
    #TEST
  CROSS APPLY
  (
    SELECT
      CASE WHEN TENURE <  90 THEN 0
           WHEN TENURE >= 90 THEN 1
                             ELSE -1 END AS IS_TENURED
  )
    AS TENURE_CHECK
  GROUP BY
    GROUPING SETS(
      (MONTH, TYPE, IS_TENURED),
      (MONTH, TYPE)
    )


MONTH
TYPE
IS_TENURED
CALCULATION


1
TYPE1
0
5.33333333333

1
TYPE1
1
6.81333333333

1
TYPE1
null
6.15555555555

1
TYPE2
0
5.55555555555

1
TYPE2
1
5.95238095238

1
TYPE2
null
5.76923076923
MONTH	TYPE	CALCULATION	NO_TENURE	TENURE
1	TYPE1	6.15555555555	5.33333333333	6.81333333333
1	TYPE2	5.76923076923	5.55555555555	5.95238095238