Please answer a question about the following article about Switzerland:

Swiss citizens are universally required to buy health insurance from private insurance companies, which in turn are required to accept every applicant. While the cost of the system is among the highest it compares well with other European countries in terms of health outcomes; patients who are citizens have been reported as being, in general, highly satisfied with it. In 2012, life expectancy at birth was 80.4 years for men and 84.7 years for women the highest in the world. However, spending on health is particularly high at 11.4% of GDP (2010), on par with Germany and France (11.6%) and other European countries, and notably less than spending in the USA (17.6%). From 1990, a steady increase can be observed, reflecting the high costs of the services provided. With an ageing population and new healthcare technologies, health spending will likely continue to rise.

What population will cause health spending to likely rise in the future?
ageing