Figure CWF6.2 shows the average writing scores for this group and for year six students in Tonga in previous PILNA cycles. The average writing score in 2021 (479.08) was lower than in 2018 (502.98) but similar to the score in 2015 (475.83). The standard deviation for the average year six reading score in 2021 (46.45) was lower than in 2015 (103.81) and 2018 (93.40). This shows that the spread of writing scores in 2021 was much narrower than in previous PILNA cycles.

Standard deviation shows how close data points are to the average. A lower standard deviation means that data points are, overall, closer to the average; a higher standard deviation means that data points are, overall, further away from the average.