The Distribution Rate is the annual rate an investor would receive if the most recently declared distribution remained the same going forward. The Distribution Rate is calculated by multiplying an ETF's distribution per share by twelve (12), and dividing the resulting amount by the ETF's most recent NAV. The Distribution Rate represents a single distribution and does not represent the ETF's total return. The 30-Day SEC Yield reflects the dividends and interest earned during the period after the deduction of fund expenses. The 30-Day Median Bid-Ask Spread is the median of the bid-ask spreads calculated at the end of each 10-second interval during each trading day over the last 30 calendar days. The bid-ask spread is calculated by dividing the difference between the national best bid and national best offer by the midpoint of the national best bid and national best offer and is expressed as a percentage.