question: When did Margaret Kenyatta (Mayor)'s mother die?
context: [["Fred Bradley (rower)", ["Frederick Bradley( 1908- date of death unknown) was an English rower."]], ["Theodred II (Bishop of Elmham)", ["Theodred II was a medieval Bishop of Elmham.", "The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997."]], ["Thomas Scott (diver)", ["Thomas Scott( 1907- date of death unknown) was an English diver."]], ["Grace Wahu", ["Grace Wahu Kenyatta (1900\u20132007) was the first wife of Jomo Kenyatta, the first president of Kenya.", "Records indicate that Wahu married Kenyatta, then known as Johnstone Kamau, around 1917 or 1919.", "She had two children with Jomo Kenyatta:", "Peter Muigai Kenyatta (1922\u20131979) and Margaret Wambui Kenyatta (1928\u20132017).", "Grace Wahu died in April 2007 at the age of 107."]], ["Albert Thompson (footballer, born 1912)", ["Albert Thompson( born 1912, date of death unknown) was a Welsh footballer."]], ["Etan Boritzer", ["Etan Boritzer( born 1950) is an American writer of children \u2019s literature who is best known for his book\" What is God?\" first published in 1989.", "His best selling\" What is?\" illustrated children's book series on character education and difficult subjects for children is a popular teaching guide for parents, teachers and child- life professionals.", "Boritzer gained national critical acclaim after\" What is God?\" was published in 1989 although the book has caused controversy from religious fundamentalists for its universalist views.", "The other current books in the\" What is?\" series include", "What is Love?,", "What is Death?,", "What is Beautiful?,", "What is Funny?,", "What is Right?,", "What is Peace?,", "What is Money?,", "What is Dreaming?,", "What is a Friend?,", "What is True?,", "What is a Family?,", "What is a Feeling?\"", "The series is now also translated into 15 languages.", "Boritzer was first published in 1963 at the age of 13 when he wrote an essay in his English class at Wade Junior High School in the Bronx, New York on the assassination of John F. Kennedy.", "His essay was included in a special anthology by New York City public school children compiled and published by the New York City Department of Education.", "Boritzer now lives in Venice, California and maintains his publishing office there also.", "He has helped numerous other authors to get published through\" How to Get Your Book Published!\" programs.", "Boritzer is also a yoga teacher who teaches regular classes locally and guest- teaches nationally.", "He is also recognized nationally as an erudite speaker on\" The Teachings of the Buddha.\""]], ["Harry Johnson (wrestler)", ["Harry Johnson( 1903- date of death unknown) was an English wrestler."]], ["Bill Smith (footballer, born 1897)", ["William Thomas Smith( born 9 April 1897, date of death unknown) was an English professional footballer."]], ["Margaret Kenyatta (mayor)", ["Margaret Wambui Kenyatta (16 February 1928 \u2013 5 April 2017) was a Kenyan politician.", "She was the daughter of the first President of Kenya, Jomo Kenyatta, and his wife Grace Wahu.", "She served as the Mayor of Nairobi from 1970 to 1976 and as Kenya's Permanent Representative to the United Nations from 1976 to 1986..", "She was thereafter appointed as a Commissioner with the Electoral Commission of Kenya from 1992 to 2002."]], ["Harry Wainwright (footballer)", ["Harry Wainwright( born 1899; date of death unknown) was an English footballer."]]]
supporting_facts: [["Margaret Kenyatta (mayor)", 1], ["Grace Wahu", 0]]
evidences: [["Margaret Wambui Kenyatta", "mother", "Grace Wahu"], ["Grace Wahu", "date of death", "2007"]]
answer: 2007