Question: When did amateur boxing become an Olympic sport?
About the article "Boxing", section "Professional vs. amateur boxing".

Candidate passages:
Yengibaryan won a bronze medal in the bantamweight division at the 1951 USSR Championships.
Yengibaryan joined the Soviet national boxing team in 1952 and was chosen by the USSR Olympic team to compete at the 1952 Summer Olympics in Helsinki, but he did not participate due to injury.
Yengibaryan and the Soviet team debuted in the European Amateur Boxing Championships at the 1953 European Amateur Boxing Championships in Warsaw.
Yengibaryan won a gold medal in the lightweight division and became the first Soviet boxer to become a European Champion.
In 1954, Yengibaryan moved up to the light-welterweight division and remained at this weight.
He won his first Soviet National Championship in 1955 and would win it again in 1956 and 1958.
Yengibaryan won an Olympic gold medal at the 1956 Summer Olympics in Melbourne.
He is only the second Soviet boxer to become an Olympic Champion after Vladimir Safronov, who won an Olympic gold medal just hours earlier.
Yengibaryan continued to win gold medals at the 1957 European Amateur Boxing Championships and 1959 European Amateur Boxing Championships.
He went to the 1960 Summer Olympics in Rome as the clear favorite, but due to receiving a shoulder injury during competition, he lost in the quarterfinals to Polish boxer Marian Kasprzyk.
After that, he decided to complete his career.
After retiring from his boxing career, he started coaching and founded the Children and Youth Sport School, which now bears his name, in Yerevan.
This school was the first of many in the USSR boxing program.
He spent 36 years as head of Armenia's national boxing academy.
Yengibaryan later became a judge in the international category.
In 1970's, he represented the USSR in the AIBA Referee Commission and acted as referee in major international competitions. 
Broad took up boxing when he joined the army in 1976.
He beat Chris McDonald in the 1980 Olympic Trials finals, where he qualified for the 1980 US Olympic Boxing team which ultimately did not compete due to political reasons.
He also beat top amateur Chris McDonald and lost a decision to Tony Tubbs. 
Mick Dowling is now a well-known boxing commentator and fight analyst.
He works primarily with Raidió Teilifís Éireann (RTÉ Sport) in their coverage of Irish amateur boxing including the IABA National Championships, European Amateur Boxing Championships, World Amateur Boxing Championships and the Olympic Games. 
  2004 European Amateur Boxing Championship: Pula  
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.