Key TakeawaysRyanair reported first-quarter profit Monday that was roughly half of what it posted a year ago.Average fares decreased 15% year-over-year, partially offset by a 10% increase in customers.The company now expects summer fares to be "materially lower than last summer." Ireland-based airline Ryanair Holdings (RYAAY) on Monday posted first-quarter profit that fell nearly 50% year-over-year, helping send its American depositary receipts (ADRs) sharply lower. The company reported profit of 360 millio ...