Unadjusted flow is calculated from ICI, Assets of Closed-End Funds by Type, Total Bond, Domestic Municipal as the current quarter's level less the previous quarter's level multiplied by one plus the percent change in a municipal bond index (FOF series FI073162003). Level is calculated at book value starting in 1994:Q4 by adding the unadjusted flow to the previous level. Data for the most recent ten years show no significant seasonality.
