I'll work on fixing my sheet.
I think there may be 5 leftover years though. In the OP, it says the war started 35 years ago, but then it says it lasted 25 years. If it lasted 25 years and then there were 5 years of political instability and civil war, then that's 30 years. You need to edit 'It lasted 25 years' to 'It lasted 30 years', otherwise there are 5 leftover years in there.
I think we are all in understanding now, but you may want to fix that so no body messes up in the future.