15%
Operational Standard
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
| 2009 | 14.728972% | 13.837988% | 11.660734% | |||||||||
| 2010 | 14.840462% | 14.331853% | 11.321360% | 12.498474% | 12.655654% | 12.224537% | 12.374289% | 13.017685% | 13.547394% | 13.940673% | 12.869056% | 11.830680% |
| 2011 | 15.838077% | 14.900154% | 11.072664% | 11.798092% | 14.087632% | 14.250839% | 12.989266% | 12.437302% | 12.844710% | 13.202186% | 12.055516% | 11.049302% |
| 2012 | 13.451942% | 13.678018% | 11.426522% | 11.892371% | 12.691117% | 13.234455% | 12.911417% | 12.163225% | 13.330512% | 12.673249% | 12.115069% | 11.566554% |
| 2013 | 14.348493% | 14.531058% | 12.052811% | 12.876102% | 14.099655% | 12.487025% | 13.119639% | 12.481529% | 14.262405% | 15.004452% | 14.910575% | 13.119130% |
| 2014 | 16.466200% | 16.125290% | 14.292571% | 13.989336% | 16.598184% | 17.278759% | 15.824628% | 15.892734% | 17.865870% | 17.614712% | 16.054688% | 15.083051% |
| 2015 | 18.749400% | 19.016460% | 15.949170% | 16.881325% | 18.814161% | 18.644068% | 18.127310% | 17.337716% | 18.467452% | 18.180265% | 16.542128% | 14.863922% |
| 2016 | 18.966803% | 18.980378% | 15.987406% | 17.190340% | 18.553191% | 17.339193% | 17.763890% | 17.205692% | 18.574621% | 18.900634% | 17.731106% | 16.952715% |
| 2017 | 20.311719% | 20.182232% | 16.967648% | 17.090304% | 18.969760% | 19.453476% | 18.597415% | 17.367417% | 17.974620% | 17.658858% | 17.518797% |