The proportion of women who are employees in each trade sector is determined from the 2013 census. This data excludes those in non-trade roles within the sector. The time series for the proportion of female employees is calculated from IRD data each quarter and the mean of the four quarters is taken for each year. This proportion is scaled by a fixed factor for each sector so that the proportion in the first quarter of 2013 matches the proportion calculated from the 2013 census.
This measure provides an estimate of the proportion of women in trade roles in each sector each year. This is subject to the caveat that, due to the high proportion of non-trade staff among women in trade sectors, changes in this measure may be driven by changes in non-trade staff rather than tradespeople.
Only employees are included in this data. The populations identified as self-employed or employers in the IRD and census datasets are too different for this scaling to be applied.