exceeding table dimensions problem?

I'm struggling with Part E (the very last part of this code)... I'm trying to find the population of each continent by dividing the total water use by per capita water use for each country. But then I need to sum that population number for each continent and then add it into a column of an already existing table. I thought the tables were the same dimension but I am getting an error on line 51 and I do not know how to fix it.

I've attached my code and the table it's pulling from. Thank you!!

[KSSV]

@Olivia Colombo

YOu have asked few questions earlier...but you have not closed them..and you are asking further questions. Please finish the existing questions and ask new ones. Like the below answer is not adressed by you yet.

https://in.mathworks.com/matlabcentral/answers/447225-separating-a-structure-field-by-unique-elements?s_tid=prof_contriblnk