Key Finding: This chart presents, per fiscal quarter, the percentage of claims that were found unpatentable or cancelled out of those challenged by the petitioner in IPR proceedings that reached final written decisions or were denied institution on substantive grounds. The data suggests that there has been a drop in unpatentability findings. It is unclear if this is due to adjustments by the PTAB, the quality of patents challenged by petitioners, the quality of petitions/defenses, or some combination thereof. The listed periods are for final written decisions. The analyzed decisions not to institute are from one year earlier.