Complex sentence: In April 2016 "New Scientist" obtained a copy of a data-sharing agreement between DeepMind and the Royal Free London NHS Foundation Trust, which operates the three London hospitals which an estimated 1.6 million patients are treated annually.
Split into simpler sentences: In April 2016 "New Scientist" obtained a copy of a data-sharing agreement between DeepMind and the Royal Free London NHS Foundation Trust. The latter operates the three London hospitals where an estimated 1.6 million patients are treated annually.