Complex sentence: This is only the third time that this kind of unrest has hit Belize; the first time was in the 1950s and the second time was in 1980s, when there was a proposal drafted to cede part of the country to Guatemala.
Split into simpler sentences: This is only the third time that this kind of unrest has hit Belize. The first time in the'50s and the second time during the' 80s when there was a proposal drafted to give part of the country to Guatemala.