Oxford reading levels

[Chickenuggetsticks]

Would someone please explain to me why the levels start from 8 twice? It’s not explained on their website.

This chart is a bit weird. I have always assumed the levels are repeated like that because of how they compare to the year groups, so levels 8-12 are normal in year 2 and year 3.

This is a poor quality image but gives a clearer idea of progression.