We include a transaction once nine months have elapsed since the closing date. This is because we expect that a transaction's performance developments are unlikely to be visible immediately after closing. As the index is current balance weighted, including transactions with less than nine months of performance will lower the index's denominator and may give an overly positive impression of performance. We assess this on a case-by-case basis. For example, we exclude equity release (reverse mortgage) and nonperforming transactions backed by residential mortgages, while we include reperforming RMBS transactions. We compile the data from investor reports based on each transaction's definition of arrears. Total delinquencies are defined as arrears for one or more calendar months. We calculate the index as
