The beginning of NR/SR competition
The 1950s and 1960s saw a period of intense market competition between NR and SR. Within 20 years, improved types of SR began to dominate industrial consumption, holding almost 71% of the market by 1979. Technological changes, including the development of radial tyres and the increasing use of NR latex products, have caused this share to drop quite rapidly since then. It is currently estimated to be just under 60%.
See NR/SR substitution for further discussion on this subject.