Precipitously

The population of the region dropped precipitously over the last decades, which prompted action by the local authorities to promote higher birth rates and attract immigration.

Source: tatoeba (5485344)

Jeff Worn, the Vice President of the South Georgia Pecan Company in Valdosta, Georgia, one of the largest pecan producers in the world, says the Chinese bought about 31 to 36 million kilograms last year, a third of the entire U.S. pecan crop last year. He says that has raised the price of pecans precipitously.

Source: tatoeba (12233850)

Population dropped to the lowest point in five millennia. State resources declined precipitously. In many strategic and formerly prosperous areas, there were tax revenue losses of 90 percent or more in less than a single lifetime.

Source: wiktionary

Never will I visit it again; it is a place of evil omen.' After a very brief halt for breakfast we pressed on with such good will that by two o'clock in the afternoon we were at the foot of the vast wall of rock that formed the lip of the volcano, and which at this point towered up precipitously above us for fifteen hundred or two thousand feet.

Source: wiktionary