No, your numbers are taken from a 4 year old US Census, my numbers are taken from SNAP data referenced all over the web.
But let's look at your source for a minute. Here is an image taken from their
June 2014 report on SNAP:
View attachment 67172400
So... 66% are not expected to work. Of the able bodied we get ... 14% working and 21% not working.
Now, granted, their pie chart adds up to 101%, so let's say that 14% are working and 20% aren't and do the math:
14/(14+20)*100= 41.2% employment rate among the able bodied SNAP recipients.
If the Census number is accurate at 58% it is likely because the anonymity of the Census meant more SNAP recipients were honest in their census paperwork than they are with their social worker.