Figure CRF6.2 shows the average reading scores for this group and for year six students in Tonga in previous PILNA cycles. The score in 2021 was lower than in 2018 and 2015, while the standard deviation for the 2021 reading score (SD = 72.14) was higher than in 2018 (SD = 59.99) and 2015 (SD = 48.03). This shows that the spread of year six reading scores in PILNA 2021 was wider than in previous years.

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.