Automatically Fill Data Depending On Choice From Drop-down Menu

Hi,
I have big problem doing the following:
I have 4 set of data for 4 regions into 4 different sheets and I have an Overall sheet where i have my drop down list. I want to be able to have the numbers related to each region gets displayed into the Overall sheet upon selecting from drop down menu. for example if i select Region 1 from the drop down menu the data inside Region 1 sheet gets displayed in the overall sheet.
I have attached my work sheet.
thanks a lot for teh help in advance