Fig. 4

The efficiency scores of different DMUs and regions. Picture a presents the efficiency scores of each DMU from 2009 to 2014; picture b shows the average efficiency score (geometric mean) of China’s mainland and the three regions. From 2009 to 2014, the average efficiency score of the eastern region of China was 0.946, 0.956, 0.949, 0.970, 1.016 and 1.019; that of the central region of China was 0.744, 0.801, 0.792 0.843, 0.865 and 0.877; and that of the western region of China was 0.962, 0.993, 1.013, 1.045, 1.021 and 0.987, which indicated that the average rate of increase in the east, central and west regions was 1.50%, 3.40% and 0.54%, respectively