The growth in New Zealand’s manufacturing sector can be seen in the increasing number of factories. The average number of people employed at each site also grew. In the years from 1951 to 1971, for example,  workers per factory went from 17.1 to 23.7. This graph is based on figures gathered in a number of different ways, using different definitions of ‘manufacturing establishment’. For instance car repair businesses were excluded after 1971; manufacturers with fewer than two employees were included after 1982. The graph shows a trend line rather than a consistent data set.