Interest on $158,806.35 from Feb 2018 to Dec = $3,639.31
Interest on $162,445.66 from Jan 2019 to Oct = $3.384.28
Accrued interest to Oct 2019 totalled $7,023.59 (due to rounding off)
I think we can overlook the 6 cents of rounding. And actually CPF is
undercalling this, because an OA repayment today would only start earning interest from December 1. That is, November's (this month's) interest is already gone.
There's yet another interesting point, and I wonder if CPF does what I'm about to describe. By rights, it should. Some individuals who use OA funds for housing also lose some bonus interest. That happens if their MA+SA+RA totals less than $60,000 (or, in rare cases among older members, less than $30,000), meaning that OA dollars are/were contributing to bonus interest, to some extent anyway. Lost bonus interest is also lost interest, so shouldn't that be included in the accrued interest figure?
....But it probably isn't, which is too bad actually. And that lost bonus interest, if/when repaid, would need to be credited to the member's Special Account (or to his/her Retirement Account if age 55 or older).