Only a couple % at most. The number staying unmarried went up by huge factors, maybe ten or 100. Not 10%, but 10 X, or 100 X.
This could change again, of course, some day when there is a shortage of people on the planet, which is not the case now. There is no shortage of people. In fact, the supply of people worldwide is growing all the time. If there is a shortage of people in your town, it is nothing but a distribution problem.
The marriage rate fell from 9.8% to 7.6%. That is only a 20% drop. I don't know the exact number but the drop in the percentage of the population that is between 18 and 30 was quite substantial.
I'm still thinking that most of this statistic is demographics. In any event, the article is stupid. To throw this statistic out as if it were indicative of important trends in male attitudes on marriage and to ignore the obvious hole in the meaning of the statistic suggests that the author is either ignorant or, more likely, trying to make a point with a statistic that he knows will sound better than it really is.