It reached 35 vehicles per 100 inhabitants, which remains well below the OECD average and the vehicle ownership rate of most OECD countries (see Annex l. A and Basic Statistics). Nonetheless, emissions of CO, NOx and particulate matter (PM) from mobile sources decreased significantly, thanks to stricter vehicle emission standards, improvement in road vehicle technology and widespread use of ethanol in cars (Figure 1.9, also see Chapter 3).