For full context, see here: https://www.docdroid.net/oraqSdS/img-20170830-0001-new.pdf
The following sentence is taken from Line 2-3: 日本では交通事故で毎年1万人くらい死んでいるが、その原因のほとんどは運転手のミスである。
First, my attempt at translation: In Japan each year around 10000 people are killed in accidents in traffic, but…it is the drivers fault.
I honestly can’t make any sense of その原因のほとんどは .
ほとんど is listed on jisho as an adverbial or temporal noun http://jisho.org/search/%E3%81%BB%E3%81%A8%E3%82%93%E3%81%A9%E3%81%8C I don’t know what a temporal noun is. I know nouns in adverbial function with a temporal meaning. Maybe this is meant here, but I can’t know for sure. And even if I knew what it is, with the english translations provided by jisho I still can’t figure out a meaningful translation.
The same btw. goes for this sentence (Line 4-5): 飛行機事故、仕事中の事故、家庭での事故、これらの原因もほとんどがヒュマンエラーである。
First, my attempt at translation: „aircraft accidents, accidents at the workplace and accidents at home, ….are human error.“
The part これらの原因もほとんどが is just as cryptic for me. I’d also like to know why も is used here, since the pattern is basically the same as before. Is も used in the function of the の of the sentence before, just with the addition that も emphasizes that the same or a similar thing is mentioned here?