Israeli universities are among 100 top world universities in mathematics (Hebrew University, TAU and Technion), physics (TAU, Hebrew University and Weizmann Institute of Science), chemistry (Technion and Weizmann Institute of Science), computer science (Weizmann Institute of Science, Technion, Hebrew University, TAU and BIU) and economics (Hebrew University and TAU). Israel has produced six Nobel Prize-winning scientists since 2002 and has been frequently ranked as one of the countries with the highest ratios of scientific papers per capita in the world. Israel has led the world in stem-cell research papers per capita since 2000.