In just 50 years the Mont Blanc massif, and Chamonix and Courmayeur in particular, had become a popular destination for many travellers, and its economy changed from 80% agriculture to 80% tourism. It saw the emergence and spread of the sport of alpine mountaineering, and visitor numbers increased significantly. By the end of the 18th century, Chamonix was home to around 1,500 summer visitors. By 1850 it was welcoming 5,000 visitors, and by 1892 those numbers had risen to 24,000 a year. In 1906, the eleventh edition of a guidebook written by Edward Whymper about Chamonix and the Mont Blanc range estimated that 130,000 visitors had gone there during the previous season. It also reported that the railway service to Chamonix, which had previously been suspended in winter, was now running throughout the year.: The tourist boom to the mountains had started. In 1924, a Winter Sports Week was held in Chamonix, with patronage from the International Olympic Committee. It attracted over 10,000 paying visitors and was retrospectively named as the first Winter Olympic Games.