Query: When was the last time the area of Bern was measured?
Context: Bern has an area, as of 2009[update], of 51.62 square kilometers (19.93 sq mi). Of this area, 9.79 square kilometers (3.78 sq mi) or 19.0% is used for agricultural purposes, while 17.33 square kilometers (6.69 sq mi) or 33.6% is forested.