Our new business production totaled $389 million of direct PVP exceeded by $75 million -- the direct PVP we produced in every year but once since 2010.
The sole exception was the $553 million of direct PVP we produced in 2019 making the last two years direct production our best in this decade.
In our core business, U.S. municipal bond insurance we guaranteed more than $21 billion of foreign primary and secondary markets, generated $292 million of PVP, both 10-year records for direct production.
We again set new per share records for shareholders' equity and adjusted operating shareholder's equity with totals at year-end of $85.66, $78.49 respectively.
During the year, our adjusted book value per share exceeded $100 for the first time.
At $114.87 year end of adjusted book value per share reflected the greatest single year increase since our IPO $17.88 and the second highest growth rate of 18%.
We retired a total of 16.2 million common shares mainly through highly accretive share repurchases at an average price of $28.23.
We spent 11% less in 2022 repurchase.
We repurchased 31% more shares than in 2019.
We returned a total of $515 million to shareholders through repurchases and dividends.
We also repurchased $23 million of outstanding debt.
2020 was a profitable year where we earned $256 million in adjusted operating income or $2.97 per share.
The benchmark 30 year AAA municipal market data interest rate began the year at 2.07%, jumped in March as high as 3.37%, bottomed down in August at a historic low of 1.27%.
At that time for PO analysts of any were predicting that 2020 will see $452 billion of municipal bonds issued the greatest annual par value on our volume on record.
These included $500 billion municipal liquid facility which reassured the bond market by providing a backup source of liquidity for states and municipal.
As a result bond insurance penetration rose to 7.6% of par volume sold in the primary market, almost a full percentage point above the past decade's previous high.
Assured Guaranty led this growth with a 58% share of insured new issue par sold.
$21 billion of U.S. public finance par we insured in 2020 was 30% more than in 2019 and included taxable and tax exempt transactions in both primary and secondary markets.
2020 PVP was up 45% year-over-year.
We insured $6.8 billion of forum taxable municipal new issues in 2020, up from $3 billion in 2019, $1.5 billion in 2018.
We also guaranteed $2.5 billion of par the new issues that had underlying ratings in the AA category from S&P or Moody's, which was $1 billion more than in 2019.
The increase in institutional demand for our guarantee was evident in 39 new issues, up from 22 in 2019 where we provided insurance in $100 million or more of par.
These include one of our largest U.S. public finance transactions in many years, $726 million of insured refunding bonds issued by Yankee Stadium, LLC.
Our production in Healthcare Finance made a strong contribution during 2020 as we guaranteed $2.7 billion of primary market par on 25 transactions.
As the only provider of bond insurance in the healthcare sector Assured Guaranty had 9.7% of all healthcare revenue bond par issued in 2020.
Additionally we guaranteed for $164 million of healthcare par across 39 different secondary market policies.
Another highlight was our reentry after seven years into the private higher education bond market where we insured a total of $690 million of par for Howard, Drexel and Seton Hall Universities.
For Howard University we insure two issues totaling $320 million in par in insured par.
Our International Public Finance business produced $82 million of PVP during 2020 even though a number of opportunities were delayed due to pandemic conditions.
In our Worldwide Structured Finance business, we executed a diverse group of transactions in the asset-backed securities, insurance capital management and other structured finance sectors and generated $16 million of PVP during 2020.
Our par exposure to credit review below investment declined by $531 million, a 6% decrease and ended the year at less than 3.5% of net par outstanding.
We have conditionally supported this agreement with the express understanding that the affected parties will work with us in good faith to make this agreement part of a more comprehensive solution one that respects our legal rights and ultimately achieves the goal of bringing the Title 3 process to adjust an expeditious conclusion.
This effort is taking place amid occurred during economic news, significant federal assistance has been unlocked, Commonwealth revenues continue to exceed the expectations underlying the Oversight Board's fiscal plans resulting in aggregate Commonwealth balances tripling over the last three years to more than $20 billion at year-end 2020 and reaching as high as almost $25 billion mid-year.
Our total net par exposure to Puerto Rico decreased in 2020 by $545 million including $372 million of water and sewer bonds that were redeemed without any claims having been made on our policy.
Even though AssuredIM assets under management in the wind down funds were reduced by $2.4 billion its total AUM changed very little declining by less than 3% to $17.3 billion.
Assured Guaranty's insurance companies have allocated $1.1 billion of investments from AssuredIM to manage, of which, almost $600 million was funded as of year-end.
As of October 1, 2020, we were pleased to learn that Assured Guaranty would become a competitor of the Standard & Poor's Small Cap 600 Index.
These investors' appetite for our shares was reflected in a 31% increase in our share price the week following the announcement.
Our share price continue to grow and in the year 44% higher than on October 1 almost doubling through February 25 of 2021.
Inclusion in the Index changed the composition of our shareholder base to be somewhat more heavily weighted toward the index focused asset managers including our second- and fourth-largest shareholders which together hold approximately 20% of our shares at year-end.
We also retired 16.2 million shares, mainly through share repurchases which helped to boost adjusted book value per share to a new record of over $114 per share.
In our Asset Management business, we increased fee earning AUM from $8 billion to $12.9 billion or 62% across CLO opportunity and liquidity strategies.
As of yearend 2020 Assured Guaranty insurance companies had $1.1 billion of invested assets that is managed by Assured Investment Management of which $562 million is through an investment management agreement and $522 million is committed to Assured Investment Management funds, which had a total return of 15.6% on the invested balances.
Turning to our fourth quarter 2020 results, adjusted operating income was $56 million or $0.69 per share compared with $87 million or $0.90 per share in the fourth quarter of 2019.
The contribution from our insurance segment for fourth quarter 2020 was $109 million compared with $133 million in fourth quarter 2019.
Net earned premiums and credit derivative revenues increased $30 million to $159 million in fourth quarter 2020 compared with the $129 million in fourth quarter 2019.
These amounts include premium accelerations of $65 million and $39 million respectively.
Total income from the insurance segment investment portfolio consists of net investment income and equity earnings of investees totaling $94 million in fourth quarter 2020 and $84 million in fourth quarter of 2019.
Net investment income represents interest income when fixed maturity and short-term investment portfolio and with $70 million in fourth quarter 2020 compared with $85 million in the fourth quarter of 2019.
In the fourth quarter 2020 equity earnings was $24 million compared to a negligible amount in fourth quarter 2019.
As of December 31, 2020 the insurance subsidiaries investment in Assured Investment Management funds was $345 million, compared with only $77 million as of December 31, 2019.
The insurance companies have authorization to invest up to $750 million in Assured Investment Management funds of which over $43 million has been committed including $177 million that has yet to be funded.
In addition, the company has a commitment to invest an additional $125 million in unrelated alternative investments as of December 31, 2020.
However, the long-term we expect the enhanced returns on the alternative investment portfolio to be approximately 10% to 12%, which exceeds the returns on the fixed maturities portfolio.
In the Asset Management segment adjusted operating income was a loss of $20 million compared with a loss of $10 million in fourth quarter 2019.
The additional net loss was mainly attributable to $5 million in placement fees associated with the launch of new healthcare strategy and an impairment of a right of lease -- right of use asset of $13 million related to the relocation of Assured Investment Management offices to 1633 Broadway, Assured Guaranty's primary New York City location.
Our long-term view of the Asset Management segment remains positive based on our recent success in increasing fee earning AUM by 62% and launching a $900 million healthcare strategy with significant third-party investment.
Adjusted operating loss for the corporate division was $28 million in the fourth quarter of 2020 compared with $32 million in the fourth quarter of 2019.
In fourth quarter 2020 the effective tax rate was a provision of 12.7% compared with a benefit of 3.5% in fourth quarter 2019.
Moving on to the full-year results, adjusted operating income was $256 million in 2020 compared with $391 million in 2019.
The variance was mainly driven by the Insurance segment and Asset Management segment adjusted operating income, which declined $83 million and $40 million respectively on a year-over-year basis.
The insurance segment had adjusted operating income of $429 million in 2020 compared with $512 million in 2019.
Net earned premiums and credit derivative revenues were $504 million in 2020 compared with $511 million in 2019 including premium accelerations of $130 million -- and a $130 million respectively.
Also, noteworthy is that public finance scheduled earned premiums increased 5% in 2020 compared with 2019.
The corporate division had adjusted operating loss of $111 million in both 2020 and 2019.
Turning to our capital management strategy, in the fourth quarter of 2020 we repurchased 4.3 million shares for $126 million at an average price of dollars and $28.87 per share.
This brings our full-year 2020 repurchases to 15.8 million shares or $446 million at an average price of $28.23.
So far in 2021 we have purchased an additional 1.4 million shares for $50 million.
Since January 2013, our successful repurchase program has returned $3.7 billion to shareholders, resulting in a 63% reduction in total shares outstanding.
The cumulative effect of these repurchases was a benefit of approximately $29.32 per share in adjusted operating shareholder's equity and $51.48 in adjusted book value per share, which helped drive these metrics to new record highs of $78.49 in adjusted operating shareholder's equity per share and $114.87 of adjusted book value per share.
From a liquidity standpoint, the holding company currently has cash and investments of approximately $204 million of which $133 million resides in AGL.

Summary:
Turning to our fourth quarter 2020 results, adjusted operating income was $56 million or $0.69 per share compared with $87 million or $0.90 per share in the fourth quarter of 2019.