4%
Operational Standard
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
| 2009 | 1.7568554% | 1.7916955% | 1.3303886% | |||||||||
| 2010 | 2.3758586% | 1.2397843% | 1.3165112% | 1.7265959% | 1.5397260% | 1.6378569% | 1.4805942% | 1.6326934% | 1.8188817% | 1.5832457% | 1.6758703% | 1.4667089% |
| 2011 | 2.3679513% | 1.5239125% | 1.4262934% | 1.5231717% | 2.0794598% | 1.5963923% | 1.4613474% | 1.6078958% | 1.7471156% | 1.5708315% | 1.5508740% | 1.3399504% |
| 2012 | 1.9104648% | 1.4514440% | 1.3346219% | 1.6478223% | 1.5203426% | 1.7601817% | 1.4590348% | 1.5024812% | 1.8584459% | 1.6401867% | 1.4895908% | 1.4128648% |
| 2013 | 2.1650141% | 1.4822387% | 1.4409222% | 1.7386007% | 1.4755907% | 1.8154312% | 1.4587121% | 1.5715702% | 1.6909648% | 1.7375826% | 1.9180431% | 1.6942789% |
| 2014 | 2.3097646% | 1.9665293% | 1.9183562% | 1.9606934% | 2.3870102% | 2.3793581% | 2.0733853% | 2.2106129% | 2.5613431% | 2.2584480% | 2.3760716% | 2.0802247% |
| 2015 | 3.1975008% | 2.2322952% | 2.2947476% | 2.6527734% | 2.3759642% | 2.5850622% | 2.1869588% | 2.4320458% | 2.5657922% | 2.2131869% | 2.2886422% | 1.9834426% |
| 2016 | 3.0500296% | 2.3040029% | 2.2688283% | 2.6237796% | 2.3364486% | 2.3377902% | 2.2030905% | 2.5888094% | 2.6352230% | 2.6027689% | 2.6771217% | 2.0543435% |
| 2017 | 3.3623285% | 2.3115578% | 2.0317781% | 2.5687034% | 2.5368082% | 2.4189704% | 2.3323258% | 2.2576832% | 2.5878554% | 2.2044088% | 2.4493857% |