Performance measure footnotes or additional information

IR includes footnotes or additional information for some performance measures. These criteria we apply to ensure disclosure of the most relevant and useful information:

• the reason for not achieving a particular target
• the reason for achieving 15% above a target
• assessment criteria used such as the survey scale
• any change in measurement methodology from the previous year
• any correction to a previously reported result 
• clarifying which products or services are included or not included in the result or the date or timing to which the data relates.