Annual unadjusted flow from BEA, NIPA . Series is calculated as Table 1.10, line 12, Net operating surplus, Private enterprises; less Table 1.14, line 24, nonfinancial corporate business net operating surplus; less households and nonprofit organizations net operating surplus ( FOF series FU156402101); less noncorporate business net national income ( FOF series FU116140001); plus noncorporate business property income interest received ( FOF series FU116130101); less noncorporate business interest paid ( FOF series FU116130001); less noncorporate business withdrawals from income of quasi-corporations ( FOF series FU116122001); less noncorporate business reinvested earnings on foreign direct investment ( FOF series FU113192281); less noncorporate business rents ( FOF series FU116112001). Quarterly unadjusted flow from unpublished detail provided by BEA . Data for the most recent ten years show no significant seasonality. Series has no levels.