This data is based on national emissions estimates released in the Bureau of Infrastructure, Transport, and Regional Economics (BITRE) Australian Infrastructure Statistics-Yearbook 2014, https://bitre.gov.au/publications/2014/yearbook_2014.aspx.
Units are as a percentage of emission levels. The word 'metropolitan' refers to the eight capital cities: Sydney, Melbourne, Brisbane, Adelaide, Perth, Hobart, Darwin and Canberra.
Data used to produce figure ATM41 of the 2016 SoE. See https://soe.environment.gov.au/theme/ambient-air-quality/topic/2016/management-sources-pollution#ambient-air-quality-figure-ATM41