I don't know how many they have: when I was in the Desert House there were at least 4 adults at the top end, but there could have been more out of sight. This young bird and another one were in the central area, but there may have been more among the rocks and cactuses as they are remarkably hard to see if they keep still. I also expect that there will be some off-show, as the first clutches were hatched in incubators.
I wouldn't be surprised if one or two of the Devonian ZooChatters know more than I do.
On the other hand, I would be surprised and disappointed if there were no tinamous or adjutants for you to see next year
