Have a look at this link and you'll see that you get:
2.5% if the deposit is locked in from 4<7 months.
5.2% if its locked in for 7<8 months
2.5% on anything from 8<12months.
How does that make any sense? aren't rates supposed to progressively increase especially within a 12 month period?
...I called them and asked why: "we offer specials".
I'm thinking they possibly need more cash/capital during certain months so they'll offer high rates for that, hence what looks like an inconsistency?