Maybe they’re estimating those seen but unreported as part of the 3%.
How would you then know they were seen?
I'm thinking that most of the world's skies are not viewable by humans most of the time, due to clouds or geography. Right off, 2/3 of the world's surface is water, so there aren't many people looking up in those areas far from land. For the skies that are viewable, most people live in areas where the light pollution obscurs all but the brightest objects. Then there is the greatest light polluter of all, the sun. I did once see what I presumed to be a meteor during the day, but it was short, quick, and over. In 47 years I've seen thousands of meteors at night, and one during the day.
Finally, statistics. Most of the best viewable times coincide with more than 99% of the human population being asleep or inside. And even if you are outside at 3am on a great viewing night, what are the odds that you will be observing that particular section of sky, during that very short duration of time?
3% just seems illogically high.