This publication presents estimates of apprentice and trainee activity in Australia for the September quarter 2012. The figures in this publication are derived from the National Apprentice and Trainee Collection no.74 (December 2012 estimates). The most recent figures in this publication are estimated (those for training activity from the March quarter 2011 to the September quarter 2012). Estimates take into account reporting lags that occur at the time of data collection. Consequently, the figures in this publication may differ from those published in earlier or later reports. Estimated data are presented in this publication on a seasonally adjusted, quarterly and 12-month ending series basis. The 12-month ending series is particularly useful in showing longer-term data trends, but is less useful in identifying turning points. The seasonally adjusted data involve the use of a mathematical model to smooth out fluctuations due to seasonal influences. Seasonally adjusted data are useful to illustrate trends from one quarter to the next, but cannot be further disaggregated. (Contains 19 tables, 3 figures and 7 notes.)