The Australian Performance of Construction Index acts as a leading economic indicator of business activity in the Australian construction industry, covering residential building, non-residential building and engineering construction. The index tracks variables including activity/sales, new orders, employment, supplier deliveries and input costs. Data is seasonally adjusted and presented in the form of diffusion indexes. A reading above 50 points indicates construction activity is generally expanding, below 50, that it is declining. The distance from 50 is indicative of the strength of the expansion or decline. Data is collected from approximately 120 companies.