What impacts the "Lost in Wilderness" population statistic?

[Atlantic Isles]

Pretty much the title- I looked at my population stats and was surprised to see that "lost in wilderness" was such a high percentage of causes of death. I crosschecked by looking at a couple other nations and it seems to be a not-insignificant amount for most nations, so I'm curious what drives this statistic. I'm also curious if an issue could be written in such a way that it would push this number down- I have a few ideas for the issue itself but I'm less clear on how I could make it achieve the intended goal.

[Union Hispanica de Naciones]

Pretty much the title- I looked at my population stats and was surprised to see that "lost in wilderness" was such a high percentage of causes of death. I crosschecked by looking at a couple other nations and it seems to be a not-insignificant amount for most nations, so I'm curious what drives this statistic. I'm also curious if an issue could be written in such a way that it would push this number down- I have a few ideas for the issue itself but I'm less clear on how I could make it achieve the intended goal.

it's probably having good enviromment, as there are more forest people lost in there.