How is the zoom percentage determined for the initial load of an Interactive Designer template?

When the Interactive Designer loads the template, the initial zoom is set to whatever is necessary to fit the entire document to display within the page. 
However this could be controlled by changing the Initial Zoom for each template(Interactive Designer Type Template) by going to eDocBuilder>Templates>Template Name(5id)>Edit Template>Template Info         Tab>Scroll down where you see Initail Zoom on the Left hand side column.