Question: In what centuries were boxing bouts known to be motivated by money?
About the article "Boxing", section "Professional vs. amateur boxing".

Candidate passages:
Throughout the 17th through 19th centuries, boxing bouts were motivated by money, as the fighters competed for prize money, promoters controlled the gate, and spectators bet on the result.
The modern Olympic movement revived interest in amateur sports, and amateur boxing became an Olympic sport in 1908.
In their current form, Olympic and other amateur bouts are typically limited to three or four rounds, scoring is computed by points based on the number of clean blows landed, regardless of impact, and fighters wear protective headgear, reducing the number of injuries, knockdowns, and knockouts.
Currently scoring blows in amateur boxing are subjectively counted by ringside judges, but the Australian Institute for Sport has demonstrated a prototype of an Automated Boxing Scoring System, which introduces scoring objectivity, improves safety, and arguably makes the sport more interesting to spectators.
Professional boxing remains by far the most popular form of the sport globally, though amateur boxing is dominant in Cuba and some former Soviet republics.
For most fighters, an amateur career, especially at the Olympics, serves to develop skills and gain experience in preparation for a professional career.
The World Series of Boxing or WSB is a professional international boxing competition that allows the professional boxers to maintain Olympic eligibility, organised by AIBA.
Unlike amateur boxing, competitors taking part in sanctioned World Series of Boxing bouts must be bare-chested and are not permitted to wear protective headgear.
Each participating boxer is drafted by one of a number of international franchises and can earn money by taking part in professional-style bouts.
However, they maintain amateur status and remain eligible to compete at the Olympic Games.
Like professional boxing, each bout is decided by the scores of three judges or, in some cases, by a knockout, technical knockout or walk-over.
A WSB meet between two international franchises consists of bouts in ten (formerly five) weight categories.
There are five three-minute rounds in each bout and the team that wins the most number of bouts wins the meet. 
Professional boxing, or prizefighting, emerged in the early twentieth century as boxing gradually attained legitimacy and became a regulated, sanctioned sport.
Professional boxing bouts are fought for a purse which is divided between the boxers as determined by contract.
Most professional bouts are supervised by a regulatory authority to guarantee the fighters' safety.
Most high-profile bouts obtain the endorsement of a sanctioning body, which awards championship belts, establishes rules, and assigns its own judges and referee.
Professional bouts are typically much longer than amateur bouts, and can last up to twelve rounds, though less significant fights can be as short as four rounds.
Protective headgear is not permitted, and boxers are generally allowed to take substantial punishment before a fight is halted.
Professional boxing has enjoyed a much higher profile than amateur boxing throughout the twentieth century and beyond.
In some countries, including Norway,Cuba and North Korea professional boxing is banned.
So was also the case in Sweden between 1970 and 2007. 
The first American sanctioning body to regulate kickboxing matches, the United States Kickboxing Association (USKA) was established in early 1970 by former Green Beret Lee Faulkner following his promotion of North America’s debut kickboxing bout featuring Joe Lewis’ knockout victory over Greg Baines.
The USKA’s rules permitted kicking, punching, knee and elbow strikes, and footsweeps.
Only crescent kicks and round kicks were allowed to the head.
Hitting below the belt and striking-and-holding were prohibited.
Bouts consisted of four by three-minute rounds inside a boxing ring, with one-minute rest periods.
Contestants wore twelve-ounce gloves and elective gym shoes or no shoes.
The USKA sanctioned only a handful of US title bouts although the organization had planned a merger with the All Japan Kick-Boxing Association for purposes of world title bouts, and even modified its name to the United States Kick-Boxing Association (USKBA), shortly before the USKA disintegrated in 1972.
The USKA succeeded, however, in arranging for the importation and weekly television broadcast of Japanese muay Thai-style "kick-boxing" bouts, with English play-by-play, over KTLA Channel 5 in Los Angeles.
This USKA should not be confused with the United States Karate Association (USKA) which affiliated karate schools and promoted the USKA Grand National Championship karate tournament. 
In the 1800s and early parts of the 1900s, many countries (and some parts of the United States) officially banned boxing, and occasionally the police (usually when they felt their bribes were insufficient) would step in to stop the unlawful bouts (which, although unlawful, were still sanctioned by regional boxing commissions).
Since boxing is now lawful almost everywhere in the world, the number of fights called "no-contest" has decreased dramatically since the beginnings of the 20th century.
Referees were also known to stop bouts during this period, when they felt bouts were too slow due to lack of aggression from one or both boxers.
In the modern game, the various rules that dictate whether a fight should be called a no contest, a disqualification, or a knockout differ between countries and boxing organizations.
Rules in the United States now dictate that any bout which ends prior to the completion of the 4th round, due to an accidental headbutt, is to be declared a no-contest.
Prior to this, accidental headbutt stoppages had been ruled a technical draw.
Most other no-contests in boxing occur when unusual circumstances, which would include instances such as a bout being rained out, ring falling apart, or an unexpected injury caused by something outside of the boxer's control.
One good example of an unusual circumstance occurred in 1983, on the undercard of the fight where Roberto Durán beat Davey Moore for the World Jr. Middleweight title at the Madison Square Garden, when Luis Resto and Billy Collins Jr boxed ten rounds.
Resto appeared to win the fight cleanly, and the scorers gave the match to Resto.
But, it was later discovered that he had cheated by tampering with his gloves before the fight.
The injuries Collins received affected his sight, and, upon finding out what Resto and his corner had done, the New York State Athletic Commission decided to change the result of the fight to a no-contest.
On August 28, 1998, Bernard Hopkins fought Robert Allen in Las Vegas, Nevada, United States.
The fight was ruled a no contest when Hopkins was injured after he was accidentally pushed out of the ring by referee Mills Lane, who was trying to break up a clinch.