Prior to the onset of economic reforms, the quality of Chinese construction was poor; as in many rural, developing countries, most structures were made from adobe or watered-down concrete and thus were ill-equipped to survive earthquakes. But in the years since, China's improvement in this regard has been striking: major cities boast modern, steel high-rises, and a far higher percentage of the population lives in earthquake-proof structures. Building codes in China are well-defined and up to international standard.