Wakeman has been married four times and has six children. At the age of 20, he married Rosaline Woolford on 28 March 1970 and had two sons, Oliver Wakeman (b. 26 February 1972) and Adam Wakeman (b. 11 March 1974). They divorced in 1977. Wakeman then married Swiss-born Danielle Corminboeuf, a recording studio secretary, in January 1980 in the West Indies and lived with her in Montreux. They had one son, Benjamin (b. 1978), before they divorced in late 1980. In 1981, Wakeman met former Page 3 girl model Nina Carter and had a daughter, Jemma Kiera (b. 1983), before they married in November 1984 and had a son, Oscar (b. 1986). The couple separated in 2000 and divorced in 2004. In 2004, Wakeman revealed that he had an extramarital affair with American-born designer Denise Gandrup, who first met Wakeman in 1972 and designed and made several of his capes. The two were romantically involved but split in 1981; they met in 1985 and had Amanda (b. 9 May 1986), but Wakeman kept it a secret to protect his marriage with Carter and agreed to financially support his daughter. In December 2011, Wakeman married journalist Rachel Kaufman.
Question: How many years had Wakeman and Jemma known each other before they were married?
Answer: 3