pre_text: Note: 1 Primarily comprises foreign exchange differences reflected in the income statement in relation to sterling and US dollar balances. Net financing costs increased by €1.3 billion, primarily driven by mark-to-market losses (including hedges of the mandatory convertible bond) and adverse foreign exchange rate movements. Net financing costs before interest on settlement of tax issues includes increased interest costs as part of the financing for the Liberty Global transaction as well as adverse interest rate movements on borrowings in foreign operations. Excluding these, underlying financing costs remained stable, reflecting consistent average net debt balances and weighted average borrowing costs for both periods.
table: Net financing costs
table: 2019 2018
table: €m €m
table: Investment income 433 685
table: Financing costs (2,088) (1,074)
table: Net financing costs (1,655) (389)
table: Analysed as:
table: Net financing costs before interest on settlement of tax issues (1,043) (749)
table: Interest income arising on settlement of outstanding tax issues 1 11
table: (1,042) (738)
table: Mark to market (losses)/gains (423) 27
table: Foreign exchange (losses)/gains1 (190) 322
table: Net financing costs (1,655) (389)
question: Analyse this data from a financial earnings document. What is the difference between the average investment income and average financing costs?