They added 1st graders in the 2016-2017 school year, 2nd graders  in the 2017-2018 school year, and added 3rd graders in the 2018-2019 school year. They'll grow to add fourth graders soon.
They incorporated 1st graders in the 2016-2017 school year, 2nd graders in the 2017-2018 school year, and added 3rd graders in the 2018-2019 school year. They're planning to add 4th graders soon.