Samuel Pufendorf (1632-1694) was a notable jurist and philosopher known for his natural law theories, influencing Adam Smith  as well as Thomas Jefferson. Olof von Dalin (1708-1763) was an influential Swedish writer and historian of the late Age of Enlightenment. Peter Wieselgren (1800-1877) was a Swedish priest, literature critic and prominent leader of the Swedish temperance movements. Knut Wicksell (1851-1926) was an influential economist, sometimes considered one of the founders of modern macroeconomics. Oscar Olsson (1877-1950) was an important developer of self-education in Sweden and known as the father of study circles. Bertil Ohlin (1899-1979) received the Nobel Memorial Prize in Economic Sciences in 1977 for theories concerning international trade and capital, and was the leader of the Liberals Peoples Party (Liberals (Sweden)) for 23 years. Gunnar Jarring (1907-2002) was Swedens ambassador in UN 1956-1958, and Swedens ambassador in Washington, D.C. 1958-1964. Britta Holmström (1911-1992) was the founder of Individuell Människohjälp (IM), a human rights organization with activities in 12 countries. Torsten Hägerstrand (1916-2004) was an internationally renowned geographer, considered the father of time geography and receiver of the Vautrin Lud Prize in 1992. Judith Wallerstein (1921-2012) was a renowned psychologist and internationally recognized authority on the effects of marriage and divorce on children and their parents.

How many years after receiving the Vautrin Lud Prize did Torsten Hagerstrand die?
12