| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Avg. | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2018 | 1,206.51 | 1,266.04 | 1,269.04 | 1,154.27 | 1,213.29 | 1,242.35 | 1,205.31 | 1,251.22 | 1,227.88 | 1,220.11 | 1,283.91 | 1,224.67 | 1,230.13 |
| 2017 | 1,181.32 | 1,229.05 | 1,255.82 | 1,144.81 | 1,196.64 | 1,240.75 | 1,201.12 | 1,241.67 | 1,245.94 | 1,152.97 | 1,264.21 | 1,216.84 | 1,214.03 |
| 2016 | 1,142.40 | 1,179.80 | 1,217.11 | 1,103.63 | 1,129.92 | 1,178.37 | 1,153.70 | 1,205.26 | 1,218.43 | 1,174.30 | 1,228.76 | 1,201.85 | 1,179.50 |
| 2015 | 1,111.19 | 1,176.00 | 1,176.01 | 1,071.98 | 1,115.40 | 1,134.17 | 1,137.05 | 1,136.33 | 1,158.60 | 1,150.01 | 1,191.13 | 1,144.46 | 1,141.60 |
| 2014 | 1,031.70 | 1,087.94 | 1,119.93 | 1,042.91 | 1,065.67 | 1,098.37 | 1,099.77 | 1,123.07 | 1,137.47 | 1,139.18 | 1,166.66 | 1,130.11 | 1,103.61 |
| 2013 | 1,096.67 | 1,118.06 | 1,154.52 | 1,040.52 | 1,093.29 | 1,115.48 | 1,102.26 | 1,124.83 | 1,099.62 | 1,103.68 | 1,116.60 | 1,032.07 | 1,099.72 |
| 2012 | 1,069.13 | 1,115.75 | 1,116.60 | 1,012.94 | 1,065.71 | 1,079.80 | 1,089.18 | 1,079.71 | 1,080.32 | 1,080.88 | 1,136.63 | 1,089.37 | 1,084.58 |
| 2011 | 995.60 | 1,033.40 | 1,065.36 | 960.00 | 999.94 | 1,053.24 | 1,036.88 | 1,054.36 | 1,077.17 | 903.29 | 1,032.59 | 1,088.16 | 1,024.00 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Avg. | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2018 | 27.25 | 28.63 | 28.73 | 26.12 | 27.42 | 28.12 | 27.33 | 28.39 | 27.80 | 27.65 | 29.18 | 27.91 | 27.87 |
| 2017 | 26.33 | 27.43 | 28.10 | 25.61 | 26.81 | 27.83 | 27.02 | 28.04 | 28.11 | 25.99 | 28.62 | 27.52 | 27.28 |
| 2016 | 24.23 | 25.02 | 25.84 | 23.48 | 23.96 | 24.97 | 24.52 | 25.92 | 26.83 | 25.97 | 27.32 | 26.81 | 25.49 |
| 2015 | 23.48 | 24.86 | 24.87 | 22.71 | 23.58 | 23.93 | 24.01 | 24.03 | 24.45 | 24.31 | 25.26 | 24.31 | 24.14 |
| 2014 | 21.73 | 22.89 | 23.57 | 21.95 | 22.43 | 23.05 | 23.12 | 23.69 | 23.95 | 24.03 | 24.65 | 23.94 | 23.25 |
| 2013 | 21.37 | 21.83 | 22.54 | 20.36 | 21.33 | 21.79 | 21.56 | 22.02 | 23.03 | 23.10 | 23.58 | 21.80 | 22.03 |
| 2012 | 20.81 | 21.64 | 21.72 | 19.76 | 20.68 | 20.96 | 21.17 | 21.05 | 21.05 | 21.04 | 22.24 | 21.36 | 21.12 |
| 2011 | 22.24 | 23.05 | 20.66 | 18.68 | 19.37 | 20.35 | 20.15 | 20.44 | 20.88 | 17.30 | 16.55 | 20.87 | 20.03 |