Calculating subtotals from SQL query

I have a query which returns some rows. Its column names are like: Age, Gender, DOB etc. What I have to do is, to check how many rows are coming from DB of which Age.

E.g. see the image:

See the age subtotal, it means my query is returning 54 rows of age 0, 1 row of age 1 and so on.

This table of subtotal must display only those ages that are returned by the query. For example there is no Age 2 as it was not returned by query.

How can I sort this issue?

Edit

Here is my Stored Procedure:

ALTER PROCEDURE [dbo].[spGetClients]
(
    @orderBy varchar(50),
    @startAge int,
    @endAge int,
    @sex varchar(5),
    @developmentalDisability varchar(200),
    @staffId nvarchar(1024), 
    @statusId nvarchar(1024), 
    @ethnicityId nvarchar(1024), 
    @treatmentProviderId nvarchar(1024)
)

AS
BEGIN
    SET NOCOUNT ON;
    
        SELECT c.Id, dbo.GetClientFullName(c.FirstName, c.MiddleInit, c.LastName) AS ClientName, 
        c.DateOfBirth, dbo.GetAge(c.DateOfBirth, GETDATE()) AS Age, c.Sex, 
        dbo.GetClientStatus(c.Id, @statusId) AS Status, ca.Address, co.Phone, 
        dbo.GetEthnicity(c.Id, @ethnicityId) AS Ethnicity, dbo.GetDevelopmentalDisabilities(c.Id, @developmentalDisability) AS Disabilities, 
        dbo.GetClientStaffContacts(c.Id, @staffId) AS Staff, dbo.GetClientContacts(c.Id) AS Contact, 
        dbo.GetClientInsuranceProviders(c.Id) AS HealthProvider, 
        dbo.GetClientTreatmentProviders(c.Id, @treatmentProviderId) AS TreatmentProvider
        FROM Client c  
        LEFT OUTER JOIN(        
            SELECT ca.ParentEntityId, ca.Address
            FROM ContactAddress ca
            INNER JOIN EntityName en ON en.Id = ca.EntityNameId AND en.Name = 'Client' 
            INNER JOIN GeneralLookup gl ON ca.glAddressTypeId = gl.Id AND gl.LookupItem = 'Primary'    
        ) ca ON c.Id = ca.ParentEntityId 
        LEFT OUTER JOIN(        
            SELECT co.ParentEntityId, co.ContactData Phone
            FROM ContactOther co
            INNER JOIN EntityName en ON en.Id = co.EntityNameId AND en.Name = 'Client' 
            INNER JOIN GeneralLookup gl ON co.glContactTypeId = gl.Id AND gl.LookupItem = 'Home'    
        ) co ON c.Id = co.ParentEntityId 
        LEFT OUTER JOIN GeneralStatus gs on gs.Id = c.StatusId
        where gs.Name <> 'Deleted' 
        and (dbo.GetAge(c.DateOfBirth, GETDATE()) BETWEEN @startAge and @endAge)
        and ((@sex = 'M' and c.sex = 'M') or (@sex = 'F' and c.Sex = 'F') or (@sex = 'Both' and (c.Sex in ('M', 'F', ''))))
        and ((@staffId = '') OR (dbo.GetClientStaffContacts(c.Id, @staffId) is not null))
        and ((@statusId = '') OR (dbo.GetClientStatus(c.Id, @statusId) is not null))
        and ((@ethnicityId = '') OR (dbo.GetEthnicity(c.Id, @ethnicityId) is not null))
        and ((@treatmentProviderId = '') OR (dbo.GetClientTreatmentProviders(c.Id, @treatmentProviderId) is not null))
        ORDER BY 
            CASE
                WHEN @orderBy = 'Consumer Name' THEN dbo.GetClientFullName(c.FirstName, c.MiddleInit, c.LastName) 
                WHEN @orderBy = 'Consumer Address' THEN ca.Address
            END
END

Your query is pretty elaborate and the output seems to be for a report, couldn't you just elaborate your sub-total in the report? (SSRS Tutorial for groups and totals)

If it is not possible, i think you could modify your stored procedure to use a Table Variable: load the query in the table and then run the various subtotal query on it.