Write a SQL query which displays geography names where Value for same month data more than 70 from the following table

Geography table

Geography Name	Period	Value
Korea	2009-04-30	10
Spain	2009-06-30	20
Sweden	2009-04-28	30
Switzerland	2009-06-30	40
Taiwan	2009-08-31	70
Thailand	2009-04-16	100
Sweden	2009-08-13	120

select
Geography,right(convert(varchar(30), Period,103),7),SUM(value) from DW.FactGeographyExposure                                                                                                                                                            group by Geography,right(convert(varchar(30), Period,103),7) having sum(value)>0