> Of the 3,142 counties in the United States, median household income declined in 222 counties (7.1 percent), while median household income increased in 521 counties (16.6 percent)

Does this mean that ~75% of counties had excatly zero change in median income? Like down to the cent? With or without inflation? This is difficult to believe. Even with stagnant wages you would expect some up and down across the whole country.