Numbers '09 includes a system for categorizing data similar to pivot tables. Pivots were introduced in Improv and were manipulated by dragging the category headers, allowing the user to quickly rotate rows into columns or vice versa. Although Numbers has similar draggable objects representing formulas, they are not used for this feature and the direct manipulation is missing. Instead, Numbers places pop-up menus in the column headers allowing the user to collapse multiple rows into totals (sums, averages, etc.) based on data that is common across rows. This is similar functionality to a pivot table, but lacks the ease of re-arrangement of the Improv model and other advanced features. Numbers 5.2, released on September 17, 2018, further improves on these features by adding Smart Categories, allowing the user to "quickly organize and summarize tables to gain new insights".