AAG ensures the payment of principal and curiosity of certain special facility revenue bonds issued by municipalities primarily to construct or enhance airport facilities and purchase gear which is leased to American. American. In each instances, the gear notes are secured by a safety curiosity within the aircraft. The 5.50% senior notes and the 4.625% senior notes are senior unsecured obligations of AAG. As well as, if we expertise specific kinds of changes of management, we must offer to repurchase the senior notes at a price of 101% of the principal amount plus accrued and unpaid interest, if any, to (however not together with) the repurchase date. The 6.125% senior notes are normal unsecured senior obligations of AAG. For the reason that inception of the share repurchase applications in July 2014, we have now repurchased 228.Four million shares of AAG widespread inventory for $9.0 billion at a weighted common cost per share of $39.41. Through the 12 months ended December 31, 2016, we repurchased 119.Eight million shares of AAG frequent inventory for $4.4 billion at a weighted average value per share of $36.86.
For the year ended December 31, 2014, we recorded a $330 million tax provision. 2017. Our pension funding obligations are probably to extend materially following expiration of the temporary funding rules, when we can be required to make contributions relating to the 2018 fiscal 12 months. Therefore, though we are going to vigorously defend ourselves in every of the actions described above and such other authorized proceedings, their final resolution and potential financial and different impacts on us are unsure but could be materials. Purchases are restricted to sure retirement profit plans, including our retiree medical and other postretirement advantages plans, resulting in a fair value classification of Level 2. Investments embrace roughly 27% of investments in non-U.S. The objectives of our funding insurance policies are to: maintain adequate earnings and liquidity to pay retirement benefits; produce an extended-term fee of return that meets or exceeds the assumed rate of return for plan property; restrict the volatility of asset performance and funded status; and diversify property among asset classes and funding managers.
Our monetary statements presently replicate these retirement packages without giving effect to any modification or termination of advantages that will ultimately be carried out based upon the outcome of this proceeding. These programs are topic to market danger. Since July 2014, our Board of Directors has permitted several share repurchase packages aggregating $9.0 billion of authority. We elected to be coated by certain particular rules for federal earnings tax purposes that permitted approximately $9.Zero billion (with $8.9 billion of unlimited NOL still remaining at December 31, 2016) of our federal NOL Carryforwards to be utilized without regard to the annual limitation usually imposed by Section 382. Similar limitations could apply for state earnings tax functions. Our capability to deduct our NOL Carryforwards and to utilize sure different available tax attributes will be considerably constrained underneath the overall annual limitation rules of Section 382 where an ownership change has occurred. Substantially all of our remaining federal NOL Carryforwards (attributable to US Airways Group) are topic to limitation underneath Section 382; nevertheless, our skill to make the most of such NOL Carryforwards will not be anticipated to be successfully constrained as a result of such limitation.
The quantity of federal NOL Carryforwards accessible in these returns is $10.5 billion, considerably all of which is anticipated to be available for use in 2017. The federal NOL Carryforwards will expire starting in 2022 if unused. We additionally had approximately $3.7 billion of NOL Carryforwards to reduce future state taxable earnings at December 31, 2016, which is able to expire in years 2017 by means of 2036 if unused. To the extent that any of the reserved shares remain undistributed upon resolution of all remaining disputed claims, such shares is not going to be returned to us however moderately shall be distributed to former AMR stockholders. We offer a valuation allowance for our deferred tax assets, which embody our NOLs, when it is extra seemingly than not that some portion, or all of our deferred tax belongings, will not be realized. In addition to the changes within the valuation allowance from operations described in the table above, the valuation allowance was additionally impacted by the adjustments within the components of accumulated different complete income (loss), described in Note 10. The overall improve in the valuation allowance was $7 million in 2016. The full lower within the valuation allowance was $4.Eight billion and $197 million in 2015 and 2014, respectively. Because of the quantity of gas wanted to operate our business, even a relatively small improve or decrease in the worth of gas can have a cloth effect on our working results and liquidity.