Question: What is the population of the city that owns Principal Park?

full_context: Document 1: Saylorville, Iowa: Saylorville is a census-designated place (CDP) in Polk County, Iowa, United States. The population was 3,301 at the 2010 census. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area. The Saydel Community School District is located in this area. The unincorporated community of Marquisville is in this area.
Document 2: Des Moines, Iowa: Age spread: 24.8% under the age of 18, 10.6% from 18 to 24, 31.8% from 25 to 44, 20.4% from 45 to 64, and 12.4% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 93.8 males. For every 100 females age 18 and over, there were 90.5 males.
Document 3: Principal Park: Principal Park, formerly Sec Taylor Stadium, is a minor league baseball stadium in Des Moines, Iowa. It is the home field of the Pacific Coast League's Iowa Cubs.
Document 4: Great American Ball Park: Great American Ball Park is a baseball stadium in Cincinnati, Ohio, which is the home field of Major League Baseball's Cincinnati Reds. It opened in 2003, replacing Cinergy Field (formerly Riverfront Stadium), their home field from 1970 to 2002. The park's name comes from Great American Insurance Group.
Document 5: Middletown, Iowa: Middletown is a city in Des Moines County, Iowa, United States. The population was 318 at the 2010 census. It is part of the Burlington, IA–IL Micropolitan Statistical Area.
Document 6: Chicago Cubs: The former location in Mesa is actually the second HoHoKam Park; the first was built in 1976 as the spring-training home of the Oakland Athletics who left the park in 1979. Apart from HoHoKam Park and Sloan Park the Cubs also have another Mesa training facility called Fitch Park, this complex provides 25,000 square feet (2,300 m2) of team facilities, including major league clubhouse, four practice fields, one practice infield, enclosed batting tunnels, batting cages, a maintenance facility, and administrative offices for the Cubs.
Document 7: Des Moines, Iowa: On September 22, 1851, Des Moines was incorporated as a city; the charter was approved by voters on October 18. In 1857, the name ``Fort Des Moines ''was shortened to`` Des Moines'', and it was designated as the second state capital, previously at Iowa City. Growth was slow during the Civil War period, but the city exploded in size and importance after a railroad link was completed in 1866.
Document 8: Johnston, Iowa: Johnston is a city in Polk County, Iowa, United States. The population was 17,278 in the 2010 census, an increase of almost 100% from the 8,649 population in the 2000 census. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area.
Document 9: Jack Trice Stadium: Jack Trice Stadium (originally Cyclone Stadium and formerly Jack Trice Field) is a stadium, in Ames, Iowa, United States. It is primarily used for college football and is the home field of the Iowa State Cyclones. It opened on September 20, 1975, with a 17–12 win over Air Force.
Document 10: Sloan Park: Sloan Park is an American baseball park in Mesa, Arizona which opened in 2014. The primary operator is the Chicago Cubs and the ballpark serves as their spring training home and is also the home of the Arizona League Cubs of the Arizona League and the Mesa Solar Sox of the Arizona Fall League. Sloan Park was built and paid for by residents of the City of Mesa, approved by ballot measure. It was primarily built to house spring training operations for the Chicago Cubs, who had previously played at nearby Hohokam Stadium. The stadium design was led by Populous. The dimensions of the playing surface closely match those of the Cubs' regular home stadium, Wrigley Field.
Document 11: Des Moines metropolitan area: The Des Moines metropolitan area, officially known as the Des Moines -- West Des Moines, IA Metropolitan Statistical Area (MSA), consists of five counties in central Iowa, United States: Polk, Dallas, Warren, Madison, and Guthrie. The 2010 census population of these counties was 569,633, and the 2017 estimated population was 645,911.
Document 12: Cedar Rapids, Iowa: As of the 2010 United States Census, the city population was 126,326. The estimated population of the three - county Metropolitan Statistical Area, which includes the nearby cities of Marion and Hiawatha, was 255,452 in 2008. Cedar Rapids is an economic hub of the state, located in the core of the Interstate 380.
Document 13: Canal Park (Akron, Ohio): Canal Park is a baseball stadium located in Akron, Ohio, United States, that is the home of the Akron RubberDucks of the Eastern League. The team is a double-A minor-league affiliate of the Cleveland Indians. Opened in 1997, the stadium was designed by Populous, the same architectural firm that designed the Indians' Jacobs Field, which opened three years earlier. The stadium takes its name from its location adjacent to the Ohio and Erie Canal, which runs behind the left-field wall.
Document 14: Highland Park Stadium: Highland Park Stadium was built as the home of the Kokomo Giants in 1955, and then Kokomo Dodgers from 1956 to 1961. The stadium generally holds 3,000 people, but findable records show 7,000 people attended a game in 1961. The stadium received its first renovation in 1985, which added most of the bleachers that are there today. 1985 was also when it hosted a minor league world series game. The stadium is due for another renovation in 2014; however, it is unclear what exactly will be redone with the stadium. Currently the stadium is just used for local games such as high school baseball teams, and the mayor, Greg Goodnight, has stated he doesn't foresee any upcoming teams in Kokomo, although he would like to see one.
Document 15: Quad Cities River Bandits: The Quad Cities River Bandits are a Class A minor league baseball team, affiliated with the Houston Astros, that plays in the Midwest League. Its home games are played at Modern Woodmen Park (formerly John O'Donnell Stadium) in Davenport, Iowa, one of the Quad Cities.
ground_truth: 645,911
sub_queries: Principal Park >> owned by Answer: Des Moines
what is the population of the Des Moines area Answer: 645,911