Non-agricultural data is mainly composed of non-agricultural employment, unemployment rate and salary, which reflects the national income and expenditure, employment and unemployment, and is a barometer of a country's economic development. Declining employment and rising unemployment rate indicate that economic development is hindered, and vice versa. Generally speaking, the unemployment rate is around 4%, but more than 9% means economic recession. The data is released by the US Department of Labor on the first Friday of each month at 2 1:30 in winter and 20:30 in summer.