A portion of the Fund's distributions may be taxable.
Some investors may be subject to Alternative Minimum Tax. 

The Fund's limited term may cause it to sell securities when it otherwise would not, which could cause the Fund's returns to decrease and the market price of the Common Shares to fall.

Premium/Discount is the percentage (%) difference between the Market price and the NAV price. When the Market price exceeds the NAV, the Fund is trading at a Premium. When the Market price is less than the NAV, the Fund is trading at a Discount.

Market Price Dividend Rate is calculated by dividing the annualized dividend rate, by the market price at month end.

NAV Price Dividend Rate is calculated by dividing the annualized dividend rate, by the NAV at month end.

Managed Assets is the Fund's total assets (including any assets attributable to leverage), minus the sum of its accrued liabilities (other than Fund liabilities incurred for the purpose of creating effective leverage (i.e. TOBs) or Fund liabilities related to liquidation preference of any preferred shares issued).

Leverage is based on the use of proceeds received from tender option bonds transactions (TOBs), issuing Preferred Shares, or funds borrowed from banks or other institutions, expressed as a percentage of Managed Assets.

Duration to Worst is the duration of a bond, computed using the bond's nearest call date or maturity, whichever comes first. This measure ignores future cash flow fluctuations due to embedded optionality.

Leverage-adjusted duration. Duration is a measure of the price sensitivity of a bond or bond fund to changes in market interest rates. Generally, the longer a bond's or fund's duration, the more the price of the bond or fund will change as interest rates change. Leverage-adjusted duration takes into account the leveraging process for a fund and therefore results in a duration that is longer than the duration of the fund's portfolio of bonds.

Percentages are based on fixed-income securities held in the Fund's investment portfolio and exclude any equity or convertible securities and cash or cash equivalents. Ratings apply to the underlying portfolio of debt securities held by the Fund and are rated by an independent rating agency, such as Standard & Poor's, Moody's, and/or Fitch. If ratings are provided by the rating agencies, but differ, the higher rating will be utilized. If only one rating is provided, the available rating will be utilized. Securities that are unrated by the rating agencies are reflected as such in the breakdown. Unrated securities do not necessarily indicate low quality. S&P rates borrowers on a scale from AAA to D. AAA through BBB represent investment grade, while BB through D represent non-investment grade.

The Bloomberg Municipal Bond Index includes approximately 15,000 municipal bonds rated Baa or better by Moody's, with a maturity of at least two years. Bonds subject to the Alternative Minimum Tax or with floating or zero coupons are excluded. The Bloomberg Municipal Bond Index is the Fund's broad-based securities market index for comparison purposes. Total returns assume the reinvestment of all dividends and capital gains. 

An investment cannot be made directly into an index. 

Call Exposure reflects the percentage of issues maturing or presently scheduled to be called from the Fund in the years specified. No assurance is made regarding whether or when the bonds may be called. Portfolio information is subject to change due to active management.