It seems that not only are we not teaching history but we are doing a poor job with basic arithmetic as well. I noticed long ago that in news stories involving figures where it is possible to check the math you can almost always find errors. It is quite common to see something where figures are quoted and then a percentage derived and the percentage is off by a huge factor. Such observations taught me long ago to take news stories with a huge lump of salt.
It could well be that the actual percentages, based on the questions asked, are proper yet the writer did a poor job of interpreting/understanding them. That would be my guess, not knowing the layout and the questions responded to.