Trust fund balance is the MRSF (Mineral Resource Stabilisation Fund) from 1975 to 1998 (the last year with a non-zero balance) from BPNG (2007). From 2005 onwards trust fund balances are obtained from the 2018 FBO. 2019 trust fund figures cannot be reconciled with 2018, and are small, so the series is discontinued in 2018. Resource revenue data is from BPNG (2007) from 1975 to 1999 and PNG Budget Database from 2000. It does not include interest earned in the MRSF (see below) but captures the sum of company tax and dividend withholding tax paid by mining and petroleum firms, other mining and petroleum taxes and mining and petroleum related dividends received by the government.