You mean the build years, or generations? Yes, there are many Gen I 2011 & 2012 Leafs on their second packs. North American 2013 Leafs made through March of 2013 are also prone to accelerated degradation, so include them with the first group. From April of 2013 through all of 2014, Nissan made a much improved pack that takes much longer to degrade, except in very hot climates. In 2015 that battery was improved again, and things were looking good for Nissan Leaf batteries - until the 30kwh battery of 2016 & 2017 appeared...
Cwerdna got his post in ahead of mine. 2014 Leafs in hot climates like AZ and FL likely make up the bulk of post 2013 pack replacements - again, until the 30kwh "Lettuce" pack.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.