http://theobamafile.com/ObamaFamily.htm
The Dunhams In 1972, When Anna divorced from Lolo, she took Barack to live with her parents, Barack's grandparents, in Honolulu. Anna and Obama's half-sister Maya returned to Indonesia.
Except for occasional visits to Hawaii, Dunham would remain in Indonesia for the remainder of her life. Shortly before her death of ovarian cancer, Anna returned to Hawaii, where she died in 1995.
But where is the evidence they divorced in 1972? That’s just a number on a website. It could be wrong. You are basing your belief on some arbitrary date on a website somewhere. Not only that, you using it to arrive at a conclusion that is pretty far-fetched when compared to the evidence (the picture).
So far I have found they divorced in 1972, the late 70’s and 1980. Don’t base your beliefs on a lack of evidence.