Year-end level from SOI, Charities and Other Tax-Exempt Organizations, table 3, Form 990 Returns of 501(c)(3)-(9) Organizations: Balance Sheet and Income Statement Items, Accounts payable, sum of columns 1 through 7. Data are annual; series is converted to quarterly by linear interpolation. Unadjusted flow is the change in the level; data for the most recent ten years show no significant seasonality.
