Erratum

-  On page 263 please note the following:

          Column 2, at age = 19: N = 6 instead of 4

          Column 4: the ‘square sign’ should be removed

          Column 6, at age = 10: the value should be 62.72 instead of 6.72

-  On page 281 please note:

           Line 1: 40 respondents should be 41 respondents

           Figure 8.19: n=40 should be n=41