With 18% of Croatia’s population, Zagreb contributed just over one-third of the country’s GDP in 2005, accounting for more than one-quarter of national employment. The city has attracted more than 75% of Croatia’s total foreign direct investment, and nearly 25,000 companies, about one-third of the country’s total, operate there. The main manufacturing industries in the city include food and beverage processing, electrical machinery, broadcasting and communications equipment, and chemicals. Because of its employment opportunities, Zagreb has attracted many migrants from other parts of Croatia, leading to overcrowded public transport and traffic congestion on the city’s main roads. Zagreb ranks 26th in the European Green City Index, with a score of 42.36 out of 100. Despite the absence of heavy industry in the city, years of neglect and underinvestment — a problem common to other post-communist countries — have had a detrimental impact on Zagreb’s environment.