The British man Colin Andrews first discovered crop circles in 1983. There were no footprints around the wheat fields with crop circles. The wheat stalks within the circles fell because of bending, and they were not broken, so it can be determined that they were not pressed by feet. Since the 1990s until now, crop circles have appeared almost every year. From the initial UK, to later North America (United States, Canada) and other countries in Europe. Especially in 1990, there were crop circles appearing in the UK almost every week, with a maximum of 75 appearing in one week.