What are the odds of becoming pregnant after your tubes are tied? percentage-wise?

<1in1000 to 20/1000: Surgical techniques (at laparoscopy, minilaparotomy...) type of procedures (clipping, single or double burns, cauterizations, Falope rings,ligations,..)the anatomical part of the tubes (isthmic, ampullary, fimbria...) the time when operation was performed (at Cesarian, after a vaginal birth, years later...) and the time interval since the operation (1, 5 or 15 years later) will affect these odds.