Cumulative and average IFs for articles from the five countries
| Year | Cumulative IF | Average IF | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| USA | UK | Japan | Germany | MC | USA | UK | Japan | Germany | MC | |
| 2005 | 5865.896 | 1056.832 | 1089.882 | 634.944 | 78.716 | 2.047 | 1.929 | 2.112 | 2.116 | 2.385 |
| 2006 | 6425.466 | 1045.266 | 1120.177 | 831.133 | 140.899 | 2.061 | 1.883 | 2.114 | 2.199 | 2.168 |
| 2007 | 6482.460 | 1195.260 | 1103.435 | 848.391 | 222.186 | 2.094 | 1.853 | 2.138 | 2.215 | 2.314 |
| 2008 | 6262.057 | 1094.861 | 1072.712 | 893.142 | 303.679 | 2.024 | 1.777 | 2.039 | 2.142 | 2.266 |
| 2009 | 7880.583 | 1135.516 | 1154.643 | 910.234 | 506.102 | 2.447 | 1.769 | 2.073 | 2.073 | 1.763 |
| 2010 | 6636.580 | 1035.284 | 1123.844 | 1084.724 | 561.488 | 2.126 | 1.681 | 2.025 | 2.135 | 1.707 |
| 2011 | 8127.619 | 1136.579 | 1178.769 | 1071.755 | 852.724 | 2.339 | 1.645 | 2.072 | 2.144 | 1.814 |
| 2012 | 7885.948 | 1311.986 | 1279.197 | 1089.660 | 997.298 | 2.087 | 1.676 | 2.508 | 2.137 | 1.885 |
| 2013 | 7716.064 | 1359.962 | 1308.423 | 1275.919 | 1279.832 | 2.387 | 1.828 | 2.035 | 2.137 | 1.888 |
| 2014 | 5048.107 | 1708.500 | 1637.344 | 1524.299 | 1555.280 | 2.305 | 1.980 | 2.057 | 2.278 | 2.025 |
| Total | 68 330.780 | 12 080.046 | 12 068.426 | 10 164.201 | 6498.204 | 2.191 | 1.802 | 2.111 | 2.162 | 1.917 |
IF, impact factor; MC, Mainland China.