storing percents

I would like to store percent values as integers ( 5 = 5%), but I would like to display the value in a formview with the percent sign. If I use
<asp:Textbox ID="pctCat1StartTextbox" runat="server" Text='<%# Bind("pctCat1Start","{0:P0}") %>' /> I get 500% instead of 5%. Is there a way to overcome this?
Thanks
 
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