Question: When did the Premier Events in Tennis begin?
About the article "Tennis", section "Premier events".

Candidate passages:
Women's tournament structure.
Premier events.
Premier events for women form the most prestigious level of events on the Women's Tennis Association Tour after the Grand Slam tournaments.
These events offer the largest rewards in terms of points and prize money.
Within the Premier category are Premier Mandatory, Premier 5, and Premier tournaments.
The Premier events were introduced in 2009 replacing the previous Tier I and II tournament categories.
Currently four tournaments are Premier Mandatory, five tournaments are Premier 5, and twelve tournaments are Premier.
The first tiering system in women's tennis was introduced in 1988.
At the time of its creation, only two tournaments, the Lipton International Players Championships in Florida and the German Open in Berlin, comprised the Tier I category.
The 2009 WTA Premier tournaments were 19 of the tennis tournaments on the 2009 WTA Tour.
The WTA Tour is the elite tour for women's professional tennis.
The WTA Premier tournaments all rank below the Grand Slam events and above the WTA International tournaments.
They are divided into three levels: Premier Mandatory (Indian Wells, Miami, Madrid and Beijing), Premier 5 (Dubai, Roma, Cincinnati, Canada and Tokyo), and Premier (10 tournaments in Europe, United States and Australia). 
Olympic Tennis Center is a proposed tennis venue that is planned to be built in Barra da Tijuca, Rio de Janeiro, Brazil.
The venue will consist of four separate tennis courts and will host the tennis events for the 2016 Summer Olympics, and the wheelchair tennis events for the 2016 Summer Paralympics.
Construction is due to begin in 2013 and be completed in 2015.
The four courts are expected to cost about $46 million. 
The possibility of being the reigning champion of all the current four Majors did not exist until 1924/25, when the International Lawn Tennis Federation designated the Australasian, French (before 1925 only open to members of French tennis clubs), British and American championship tournaments as the four Majors.
Before that time only three events: Wimbledon, the World Hard Court Championships (held in Paris & once in Brussels) and the World Covered Court Championships (held in various locations) were considered the premier international tennis events by the ILTF.
Tony Wilding of New Zealand won all three of those earlier majors in one year – 1913.
It has been possible to complete a Grand Slam in most years and most disciplines since 1925.
It was not possible from 1940 to 1945 because of interruptions at Wimbledon, the Australian and French opens due to the Second World War, the years from 1970 to 1985 when there was no Australian tournament in mixed doubles, and 1986 when there was no Australian Open at all. 
The 2012 Apia International Sydney was a joint ATP and WTA tennis tournament, that was played on outdoor hard courts.
It was the 120th edition of the Apia International Sydney, and was a part of the ATP World Tour 250 series of the 2012 ATP World Tour, and of the WTA Premier tournaments of the 2012 WTA Tour.
Both the men's and the women's events took place at the NSW Tennis Centre in Sydney, Australia, from 8 January to 15 January 2012.
Due to rain, the Men's Singles and Double's finals had to be rescheduled from the evening of 14 January to the morning of 15 January, the day before the Australian Open was due to begin.