The population for the AES 2013 financial year was 444,479 units, consisting of:

• 312,462 (70.3 percent) sourced from IR10 information
• 16,277 (3.7 percent) sourced from the postal survey
• 5,305 (1.2 percent) sourced from other government data
• 479 (0.1 percent) sourced from Ministry of Business, Innovation and Employment data
• 109,956 (24.7 percent) non-sample units.

In the AES 2013, we weighted the postal survey unit responses to represent the non-sample units. The corporate response rate required for the postal collection is set at 85 percent of the industry's goods and services tax (GST) sales. The response rate in 2013 was 90 percent.