This chart also categorizes pharmaceutical claims into four groups: compound, composition (which includes formulation), method of treatment, and process of preparing. However, this chart evaluates unpatentability/cancellation rates relative to claims instituted. Again, note that the sample size for compound claims is still small (171 claims). These statistics do not account for redundancies (which were deemed immaterial). Again, the claims were categorized based on the class as claimed, rather than attempting to determine a likely key claim feature in the body of the claim.