by more than minus 30%, 30%, 30%, and 40%, respectively. Given the current low interest rate environment, no downward rate shifts were modeled in our income simulations. At December 31, 2020, the income simulations show that a rate shift of +100, +200, +300 and +400 basis points in interest rates up will vary projected net interest income for the coming 12-month period by +11.59%, +24.98%, +37.86%, and +50.41%, respectively. The basis point shift in interest rates is a hypothetical rate scenario used to calibrate risk and does not necessarily represent management’s current view of future market developments. We believe that we are properly positioned for a potential interest rate increase or decrease.
All the measurements of risk described above are made based upon our business mix and interest rate exposures at the particular point in time. The exposure changes continuously as a result of our ongoing business and our risk management initiatives. While management believes these measures provide a meaningful representation of our interest rate sensitivity, they do not necessarily take into account all business developments that have an effect on net income, such as changes in credit quality or the size and composition of the statement of condition.
Our principal sources of liquidity and funding dividends from subsidiaries and borrowed funds, with such funds being used to finance our cash flow requirements. We closely monitor the dividend restrictions and availability from our Subsidiary Banks as disclosed in Note 20 to the Consolidated Financial Statements. At December 31, 2020, the aggregate amount legally available to be distributed to us from our Subsidiary Banks as dividends was approximately $948,000,000, assuming that each Subsidiary Bank continues to be classified as “well-capitalized” under the applicable regulations in effect at December 31, 2020. The restricted capital (capital and surplus) of our Subsidiary Banks was approximately $1,200,185,000 as of December 31, 2020. The undivided profits of our Subsidiary Banks were approximately $1,351,802,000 as of December 31, 2020.
At December 31, 2020, we had outstanding $436,327,000 in other borrowed funds and $134,642,000 in junior subordinated deferrable interest debentures. In addition to borrowed funds and dividends, we have a number of other available alternatives to finance the growth of our Subsidiary Banks as well as future growth and expansion.
Capital
We maintain an adequate level of capital as a margin of safety for our depositors and shareholders. At December 31, 2020, shareholders’ equity was $2,177,998,000 compared to $2,118,053,000 at December 31, 2019, an increase of $59,945,000, or 2.8%. Shareholders’ equity increased primarily due to the retention of earnings, offset by the payment of cash dividends to shareholders and repurchases of our common stock in the form of treasury stock. The accumulated other comprehensive income is not included in the calculation of regulatory capital ratios.
During 1990, the FRB adopted a minimum leverage ratio of 3% for the most highly rated bank holding companies and at least 4% to 5% for all other bank holding companies. Our leverage ratio (defined as shareholders’ equity plus eligible trust preferred securities issued and outstanding less goodwill and certain other intangibles divided by average quarterly assets) was 14.92% at December 31, 2020 and 16.65% at December 31, 2019. The core deposit intangibles and goodwill of $282,532,000 as of December 31, 2020, are deducted from the sum of core capital elements when determining our capital ratios.
The FRB has adopted risk-based capital guidelines which assign risk weightings to assets and off-balance sheet items. The guidelines also define and set minimum capital requirements (risk-based capital ratios). Under the final 1992 rules, all banks are required to have Tier 1 capital of at least 4.0% of risk-weighted assets and total capital of 8.0% of risk-weighted assets. Tier 1 capital consists principally of shareholders’ equity plus trust preferred securities issued and outstanding less goodwill and certain other intangibles, while total capital consists of Tier 1 capital, certain debt instruments and a portion of the reserve for loan losses. In order to be deemed well-capitalized pursuant to the regulations, an institution must have a total risk-weighted capital ratio of 10%, a Tier 1 risk-weighted ratio of 8% and a Tier 1 leverage ratio of 5%. We had risk-weighted Tier 1 capital ratios of 20.25% and 19.80% and risk weighted total capital ratios of 21.40% and 20.46% as of December 31, 2020 and 2019, respectively, which are well above the minimum regulatory requirements and exceed the well-capitalized ratios (see Note 20 to Notes to Consolidated Financial Statements).
In July 2013, the Federal Deposit Insurance Corporation (“FDIC”) and other regulatory bodies established a new, comprehensive capital framework for U.S. banking organizations, consisting of minimum requirements that increase both
