Are Sabiki rig hook sizes larger as the number goes up?

I went online to buy some Sabiki rigs today and saw that the hook sizes appeared to be backwards. Specifically, as the hook sizes went up to a #2, the main and branch line test was around 5 lbs, while at #12, the main and branch line test went up to 40 lbs. In general, do the hook sizes increase as the number goes up? Or do the sizes refer to the Sabiki rigs themselves? Very confused!