Table:
text: Men's pole vault world record progression
Record Progression
Record Progression
Record Athlete Nation Venue Date_
4.78 m Robert Gutowski United States Palo Alto , U.S. April 27, 1957
4.80 m Don Bragg United States Palo Alto , U.S. July 2, 1960
4.83 m George Davies United States Boulder , U.S. May 20, 1961
4.89 m John Uelses United States Santa Barbara , U.S. March 31, 1962
4.93 m Dave Tork United States Walnut , U.S. April 28, 1962
4.94 m Pentti Nikula Finland Kauhava , Finland June 22, 1962
5.00 m Brian Sternberg United States Philadelphia , U.S. April 27, 1963
5.08 m Brian Sternberg United States Compton June 7, 1963
5.13 m John Pennel United States London , England August 5, 1963

Question: What is the record with a date that is May 20, 1961 for the development of the world record in the men's pole vault?