The figures shown in the tables have been subjected to a confidentiality procedure known as random rounding to prevent the possibility of associating statistical data with any identifiable individual. Under this method, all figures, including totals and margins, are randomly rounded either up or down to a multiple of '5,' and in some cases '10.' While providing strong protection against disclosure, this technique does not add significant error to the census data. The user should be aware that totals and margins are rounded independently of the cell data so that some differences between these and the sum of rounded cell data may exist. Also, minor differences can be expected in corresponding totals and cell values among various census tabulations. Similarly, percentages, which are calculated on rounded figures, do not necessarily add up to 100%. Order statistics (median, quartiles, percentiles, etc.) are computed in the usual manner.
Changes have been made in the language classification used in our products. In this appendix, the 2011, 2006, and 2001 classifications are compared.

Please note that in the second part of the question on home language, the respondent had the option of marking the 'No' circle to indicate that there was no other language spoken on a regular basis.

The individual categories used in 2011 do not always match those used in 2006 and 2001. In most cases, however, the corresponding number can be obtained by adding all members of the language family.

Appendix D: Mother tongue and home language: classifications from 2011.pdf