Methodological and terminological changes were made in 1998 to conform to the requirements of both the 1993 System of National Accounts (SNA) and the UK National Accounts.
Gwnaed newidiadau methodolegol a therminolegol ym 1998 i gydymffurfio â gofynion System Cyfrifon Cenedlaethol (SNA) 1993 a Chyfrifon Cenedlaethol y DU.