How many time has the constitution has been written and re-written?

This is for Texas history

According to historical records the exact number of rewrites in full or in part is unknown, but it was changed several time before being sent to congress and each state government for ratification. Two of the colonies refused to ratify until after George Washington was elected others refused to sign without a "Bill of Rights". Except for the now existing "27 Ammendments" it has remained unchanged since 1789.