 Complete the following phrase:  The hill originally constructed by Kristian Hovde was opened in 1936 as a large hill. It was rebuilt as ski flying hill in 1964, and was modified in 1989, 1999 and 2010. The present large hill was built in 1988. Vikersundbakken was the first ski flying hill to receive floodlights in 2006. It has hosted the FIS Ski Flying World Championships in 1977, 