From that article: "According to the Department of Education, between 1992 and 2003 the average adult’s skill in reading prose slipped one point on a five-hundred-point scale..."
I don't know if this sentence is meant to raise alarms about the public's literacy or about journalists' numeracy. Without having seen the study itself, I'm going to guess that 0.2% is within its margin of error.
The first page makes a lot of slippery statistical arguments about people 'reading less,' but there's no factual connection between the opening numerical salvo and the transition on page 2: "...some sociologists speculate that reading books for pleasure will one day be the province of a special 'reading class'..."
Older people have always thought that younger people are stupid and illiterate, and that future young people will be even stupider and more illiterate.
