The INS has the population per age tranche -Census 2014-and since their age tranches are broken by 5 years we can estimate that the number of eligible starts from 15 years old (in 2018 they're 19) So we're missing an addition of one-year tranche 18-19. But then there is Death number which could…

The ISIE extended registration after 10-08-2017, and released new registration numbers in February 2018(PDF format) but the data wasn't as structured as the early released in 10-08.Data misses age tranche per gender and it contains different age tranches than the first model of 10-08.