Estimating Rental Burden (GRAPI) by Race of Householder

Hi all, 

I'd like to estimate rent burden by race of householder by state in Stata using iPUMS data. To verify my methodology, I've first tried to recreate ACS estimates for rent burden from tables S2503 and CP04. I'm able to accurately estimate the number of rentals (renter occupied housing units, row 2) in S2503. However, when I try to estimate the burden (CP04 GRAPI at the very bottom), I am consistently off by several percentage points. 

One guess I have about why I am unable to correctly estimate GRAPI is that is appears ACS drops ~3m households from the analysis when calculating GRAPI (at the US level, number vary by state), and I cannot recreate this step. It's also possible there's also something else entirely going wrong. 

I've put the details of how I've set up my estimations below, grateful for any advice you might have!

I've svyset my data like this: svyset cluster [pweight = hhwt], strata (strata) vce(linear) singleunit(center)

In addition to the weights and id variables, I'm using: ownershpd rentgrs hhincome gq statefip raced hispand

gen monthincome=hhincome/12
gen grapi=rentgrs/monthincome

gen burden=0
replace burden=1 if grapi>.349

gen renters=0
replace renters=1 if ownershpd==22 | ownershpd==21

gen black=0
replace black=1 if race==2

svy, subpop(renters): mean burden, over (statefip black)