Table 1.

Frequency and percentage distribution according to Flesch–Kincaid Grade Level scores

UK key stage	US grade	Age group, years	Frequency of PIL per level	%	Cumulative per cent of PILs
1	1	6–7	2	0.6	0.6

2	2	7–8	4	1.2	1.7
	3	8–9	3	0.9	2.6
	4	9–10	13	3.8	6.4
	5	10–11	19	5.5	11.9

3	6	11–12	43	12.5	24.3
	7	12–13	62	18.0	42.3
	8	13–14	70	20.3	62.6

4	9	14–15	63	18.3	80.9
4	10	15–16	39	11.3	92.2

Sixth form	11	16–17	16	4.6	96.8
Sixth form	12	17–18	7	2.0	98.8

University	13	18 and up	3	0.9	99.7
University	14	18 and up	1	0.3	100.0

Total			345	100.0	100.0