Grouping Count Question

Hello,

I have a query that in the end is to return totals by racial groups. In addition to grouping and counting on race I want to group based on percents. For example I want totals for all the racial groups for <=7%, >7% - <=9%, and >9%. The percents are stored in the hga1cpercent field which is also referenced when the race count is got but it isn't grouping on the hga1cpercent because I am not sure how to set up a grouping that requires columns be assigned to different groups. Is that possible? The percents are actually stored as numbers so 7 not 7% if that matters. Any help would be greatly appreciated! :)

With Diabetes(person_id) as
(
select distinct person_id from
(select count(*) as countperson,a.person_id,a.date_of_birth,
(2008-year(a.date_of_birth)) as age
from person a
join diabetes_ b on a.person_id = b.person_id
join patient_encounter c on a.person_id = b.person_id
where year(c.create_timestamp) = '2008'
group by a.person_id,a.date_of_birth)tmp
where tmp.age >=18 and tmp.countperson >=2
)
select count(*), b.race,a.hga1cpercent,max(a.create_timestamp)
from Diabetes tmp
join diabetes_flwsheet_ a on tmp.person_id = a.person_id
join person b on tmp.person_id = b.person_id
group by b.race,a.hga1cpercent