Fig. 5: Economic output of various urban scales and coastal cities at different ages (Unit: 100 million yuan).

X-axis represents coastal cities and different urban scales, Y-axis is the age of urban land, and Z-axis represents the total economic output. A Urban land in 1995, B Urban land in 2000, C Urban land in 2005, D Urban land in 2010, E Urban land in 2015, and F Urban land in 2020.