Passage: The early 1980s witnessed an escalation of violence across the country, and many predicted civil war. This was accompanied by economic stagnation as various multinational banks—under pressure from an international lobby—had stopped investing in South Africa. Numerous banks and Thatcher asked Botha to release Mandela—then at the height of his international fame—to defuse the volatile situation. Although considering Mandela a dangerous "arch-Marxist", in February 1985 Botha offered him a release from prison if he "unconditionally rejected violence as a political weapon". Mandela spurned the offer, releasing a statement through his daughter Zindzi stating, "What freedom am I being offered while the organisation of the people [ANC] remains banned? Only free men can negotiate. A prisoner cannot enter into contracts."In 1985, Mandela underwent surgery on an enlarged prostate gland, before being given new solitary quarters on the ground floor. He was met by "seven eminent persons", an international delegation sent to negotiate a settlement, but Botha's government refused to co-operate, calling a state of emergency in June and initiating a police crackdown on unrest. The anti-apartheid resistance fought back, with the ANC committing 231 attacks in 1986 and 235 in 1987. The violence escalated as the government used the army and police to combat the resistance, and provided covert support for vigilante groups and the Zulu nationalist movement Inkatha, which was involved in an increasingly violent struggle with the ANC. Mandela requested talks with Botha but was denied, instead secretly meeting with Minister of Justice Kobie Coetsee in 1987, and having a further 11 meetings over the next three years. Coetsee organised negotiations between Mandela and a team of four government figures starting in May 1988; the team agreed to the release of political prisoners and the legalisation of the ANC on the condition that they permanently renounce violence, break links with the Communist Party, and not insist on majority rule....

Question: Which year did the ANC commit the most attacks?
1987