Looks roughly 100k units with the best year being 30k. So figure Nissan has 3+ years before having to worry about the 200k limit.
Looking at cumulative numbers, Tesla is catching up. If they continue their current pace, there could be more Model S's on US roads than Leafs in about a year. Nissan better get Leaf 2 out soon or it could lose the very significant bragging rights of being the best sold EV car in the US. Being #1 does carry some weight with consumers. It would be a shame if Nissan lost that advantage.