| 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | |
|---|---|---|---|---|---|---|
| % | % | % | % | % | % | |
| Jan | 4.0 | 2.6 | 1.3 | 1.1 | 2.8 | 3.3 |
| Feb | 3.2 | 1.3 | 1.0 | 2.7 | 3.2 | |
| Mar | 3.1 | 1.6 | 0.9 | 2.5 | 3.3 | |
| Apr | 3.5 | 1.3 | 0.9 | 2.5 | 2.9 | |
| May | 3.7 | 1.4 | 1.0 | 2.4 | 3.1 | |
| Jun | 3.5 | 1.6 | 1.0 | 2.6 | 3.3 | |
| Jul | 3.6 | 1.9 | 1.0 | 2.5 | 3.1 | |
| Aug | 3.9 | 1.8 | 1.1 | 2.4 | 3.3 | |
| Sep | 3.9 | 2.0 | 0.8 | 2.3 | 3.2 | |
| Oct | 4.0 | 2.0 | 0.7 | 2.3 | 2.6 | |
| Nov | 3.9 | 2.2 | 1.1 | 2.0 | 2.6 | |
| Dec | 4.1 | 2.5 | 1.2 | 1.6 | 2.7 |