by how much did the long-term debt and redeemable preferred stock at redemption value portion of the capital structure increase since 2016?
allows us to repurchase shares at times when we may otherwise be prevented from doing so under insider trading laws or because of self-imposed trading blackout periods . subject to applicable regulations , we may elect to amend or cancel this repurchase program or the share repurchase parameters at our discretion . as of december 31 , 2018 , we have repurchased an aggregate of 4510000 shares of common stock under this program . credit facilities and short-term debt we have an unsecured revolving credit facility of $ 2.25 billion that expires in june 2023 . in march 2018 , awcc and its lenders amended and restated the credit agreement with respect to awcc 2019s revolving credit facility to increase the maximum commitments under the facility from $ 1.75 billion to $ 2.25 billion , and to extend the expiration date of the facility from june 2020 to march 2023 . all other terms , conditions and covenants with respect to the existing facility remained unchanged . subject to satisfying certain conditions , the credit agreement also permits awcc to increase the maximum commitment under the facility by up to an aggregate of $ 500 million , and to request extensions of its expiration date for up to two , one-year periods . interest rates on advances under the facility are based on a credit spread to the libor rate or base rate in accordance with moody investors service 2019s and standard & poor 2019s financial services 2019 then applicable credit rating on awcc 2019s senior unsecured , non-credit enhanced debt . the facility is used principally to support awcc 2019s commercial paper program and to provide up to $ 150 million in letters of credit . indebtedness under the facility is considered 201cdebt 201d for purposes of a support agreement between the company and awcc , which serves as a functional equivalent of a guarantee by the company of awcc 2019s payment obligations under the credit facility . awcc also has an outstanding commercial paper program that is backed by the revolving credit facility , the maximum aggregate outstanding amount of which was increased in march 2018 , from $ 1.60 billion to $ 2.10 billion . the following table provides the aggregate credit facility commitments , letter of credit sub-limit under the revolving credit facility and commercial paper limit , as well as the available capacity for each as of december 31 , 2018 and 2017 : credit facility commitment available credit facility capacity letter of credit sublimit available letter of credit capacity commercial paper limit available commercial capacity ( in millions ) december 31 , 2018 . . . . . . . . $ 2262 $ 2177 $ 150 $ 69 $ 2100 $ 1146 december 31 , 2017 . . . . . . . . 1762 1673 150 66 1600 695 the weighted average interest rate on awcc short-term borrowings for the years ended december 31 , 2018 and 2017 was approximately 2.28% ( 2.28 % ) and 1.24% ( 1.24 % ) , respectively . capital structure the following table provides the percentage of our capitalization represented by the components of our capital structure as of december 31: .

|  | 2018 | 2017 | 2016 |
| :--- | :--- | :--- | :--- |
| Total common shareholders' equity | 40.4% | 41.0% | 42.1% |
| Long-term debt and redeemable preferred stock at redemption value | 52.4% | 49.6% | 46.4% |
| Short-term debt and current portion of long-term debt | 7.2% | 9.4% | 11.5% |
| Total | 100% | 100% | 100% |

.

increase = 0.524 - 0.46399999999999997
answer = increase * 100