I worked in the airline industry for many years. Aircraft weight and balance calculations are critical to flight safety and are usually based on standard weights which are derived from survey data conducted by aviation authorities or by the airlines. These standard weight assumptions for male, female, children and infant passengers and crew, including carry-on baggage, are detailed in their operational procedures. These standard weights do change over the years. For example, internet research suggests that the European Aviation Safety Agency (EASA) calculates the average weight of a male passenger at 84.6 kg and females at 66.6 kg whereas the Federal Aviation Administration (FAA) estimates adult male and female passengers at 90.7 kg and 81.2 kgs in summer changing to 93 kg and 83.5 kg in winter), including carry-on baggage.