Year-end level from ICI, Investment Company Factbook, Table 58 Total Net Assets of Institutional Investors in Mutual Funds by Type of Institution and Type of Fund, column Business corporations, Total less Money market funds. Annual capital gains are calculated as the level multiplied by the ratio of capital gains to the level of total assets for all mutual funds ( FOF series FR654090000/FL654090000). Annual unadjusted flow is calculated as the change in the level less the capital gains and is converted to quarterly by dividing by four. Quarterly levels are calculated as the previous level, plus quarterly capital gains calculated using the same ratio as above, plus the quarterly unadjusted flow. Data for the most recent ten years show no significant seasonality.