Why did half the people in eyam survive the plague outbreak?

they had an unusual genetic mutation that prevented them from becoming infected

Explanation:

In 1665-1666, in an English village called Eyem, 260 people died from bubonic plague. The plague had entered the village in a bale of cloth that had come from London. Only 86 people survived and it is said that the reason why they survived even though they had been in contact with infected people was that they had a genetic mutation known as "Delta 32". This gene was found in the descendants of the survivors.

for starters, there is the structural trend of rising primary government expenditure as a share of gdp, which reached 36% in 2014, up from 22% in 1991. this increase reflected a political desire to address the poverty and inequality that had gone unaddressed during previous decades. to support the increase, brazil’s government increased taxes on consumption and promoted progress toward labor-market formalization. nonetheless, public investment, particularly in infrastructure, took a hit. in fact, with the exception of the 2005-2008 period, total investment as a share of gdp has remained below 20% since 1991.