I'd have to load up some old saves to see how much food it takes an AI city to grow. I know quite well that it takes 12 to go from size 1 to size 2 (same as me) and the food box fills by two food per turn (the AI cities are producing four food at size 1).
As far as shields go, the AI cities are currently showing two shields (1 for the city and one for a grassland with a shield) and are building 3 shields per turn on a legion. When the AI city grows to size 2 (before being knocked back down) the city's three shields put 4 on a legion in one turn.
For the larger cost items that I build, the rows can extend to 12, 16 or 20 shields per row.
I haven't checked on the exact version of the game that I have, but two years ago my wife picked up a number of new copies at the store for $5 each (they made some nice gifts for the birthday parties our son went to).