Strange then DMcG that the example you give defines the start of your selected "given period" to an event as opposed to merely the date.

To say that we have had only three nation wide referenda in the last 1000 years is both meaningless and ridiculous for a whole host of reasons. But to say that since referenda have been used in the UK we have only had three nation wide referenda clearly shows the frequency they are adopted - seldom and only ever on issues where free choice is offered completely uncluttered by the demands of Party Politics.