How many Grand Slam titles did the winner of the 1980 Avon Championships of Houston win ? 
39
Title: 1980 Avon Championships of California
Passage: The 1980 Avon Championships of California, also known as the Avon Championships of Oakland, was a women's tennis tournament played on indoor carpet courts at the Oakland Coliseum in Oakland, California in the United States that was part of the 1980 Avon Championships Circuit.  It was the ninth edition of the tournament and was held from February 11 through February 17, 1980.  First-seeded Martina Navratilova won the singles title, her second consecutive at the event, and earned $30,000 first-prize money.
Title: Billie Jean King
Passage: Billie Jean King ("née" Moffitt; born November 22, 1943) is an American former World No. 1 professional tennis player.  King won 39 Grand Slam titles: 12 in singles, 16 in women's doubles, and 11 in mixed doubles.  King won the singles title at the inaugural WTA Tour Championships.  King often represented the United States in the Federation Cup and the Wightman Cup.  She was a member of the victorious United States team in seven Federation Cups and nine Wightman Cups.  For three years, King was the United States' captain in the Federation Cup.
Title: 1980 Avon Championships of Houston
Passage: The 1980 Avon Championships of Houston was a women's tennis tournament played on indoor carpet courts at the Summit in Houston, Texas in the United States that was part of the 1980 Avon Championships Circuit.  It was the 10th edition of the tournament and was held from February 25 through March 2, 1980.  Third-seeded Billie Jean King won the singles title and earned $30,000 first-prize money.
1980 Avon Championships of Houston Billie Jean King