The first Sky television rights agreement was worth £304 million over five seasons. The next contract, negotiated to start from the 1997–98 season, rose to £670 million over four seasons. The third contract was a £1.024 billion deal with BSkyB for the three seasons from 2001 to 2002 to 2003–04. The league brought in £320 million from the sale of its international rights for the three-year period from 2004 to 2005 to 2006–07. It sold the rights itself on a territory-by-territory basis. Skys monopoly was broken from August 2006 when Setanta Sports was awarded rights to show two out of the six packages of matches available. This occurred following an insistence by the European Commission that exclusive rights should not be sold to one television company. Sky and Setanta paid £1.7 billion, a two-thirds increase which took many commentators by surprise as it had been widely assumed that the value of the rights had levelled off following many years of rapid growth. Setanta also hold rights to a live 3 pm match solely for Irish viewers. The BBC has retained the rights to show highlights for the same three seasons (on Match of the Day) for £171.6 million, a 63 per cent increase on the £105 million it paid for the previous three-year period. Sky and BT Group have agreed to jointly pay £84.3 million for delayed television rights to 242 games (that is the right to broadcast them in full on television and over the internet) in most cases for a period of 50 hours after 10 pm on matchday. Overseas television rights fetched £625 million, nearly double the previous contract. The total raised from these deals is more than £2.7 billion, giving Premier League clubs an average media income from league games of around £40 million-a-year from 2007 to 2010.
Question: How many years was the average income media about £40 million-a-year for Premier League clubs?
Answer: 3