| Carbon monoxide concentrations, 1996–17 | Environmental Reporting | Ministry for the Environment | Creative Commons Attribution 4.0 International | Table | Table | 5490 | 40 | ||
| Carbon monoxide concentrations and exceedances 2005–2013 | Environmental Reporting | Ministry for the Environment | Creative Commons Attribution 3.0 New Zealand | Table | Table | 5151 | 30 |