Ports are extremely important to the global economy, responsible for 70% of global merchandise trade by value. For this reason, ports are often high-concentrations of the global population—providing the labor for processing and handling the goods and related services for the ports. Today, by far the greatest growth in port development is in Asia, the continent with some of the world's largest and busiest ports, such as Singapore and the Chinese ports of Shanghai and Ningbo-Zhoushan. As of 2020, the busiest passenger port in the world is the Port of Helsinki in Finland. However, ports can also be very small and only serve local fishing or tourism.