The BSA states " Not every boy who joins a Boy Scout troop earns the Eagle Scout rank; only about 5 percent of all Boy Scouts do so. "
In 2010 there were 898,186 Boy Scouts and 56,176 Eagle Scout awards presented, thus it would appear to be 6.2%. But male Venturers who earned First Class in a troop can continue to work towards Eagle Scout while in a crew. There were a total of 238,846 Venturers, but we don't know how many were eligible, but the percentage goes down.
As of 2008 (the last year I have totals), there had been 83,486,083 Scouts since 1911 and 1,880,905 Scouts had earned Eagle Scout, making it 2.2% for the total.
The BSA has not released detailed statistics on Eagle Scouts by age, race, ethnicity or religion.
The BSA registration forms make race self described and optional so there are no accurate records of membership or awards / ranks sorted that way. It is believed that Arican Americans are underrepresented in Scouting in general, a situation the BSA is actively attempting to correct, with about 11% of scouts estimated to be African. About 4% of scouts earn their Eagle but weather an African American scout is more, equally, or less likely to attain Eagle is unknown.
Less than 1/10th of 1%
Eagle scouts can be anything they want to be or can have any talent they want. -- There are a lot of former scouts who are singers, but doesn't look like Eagle Scouts. The links have lists of famous scouts who became singers.
To be honest, I don't believe this statistic has been studied.
No, but many have been Scouts.
181 NASA astronauts were involved in Scouting, and 39 are Eagle Scouts
The BSA has not released any data on Eagle Scouts by age.
Eagle Scout is considered to be awarded when the board of review is signed off. The ceremony is held at the unit level and is not mandatory. Whether or not a ceremony is held is not reported, so there is no answer to this question.
Utah
The United States has sent 312 people into space. 39 of them are or were Eagle Scouts. 207 of them had some scouting experience.
About 2% of scouts make Eagle Scout