The number of watches Switzerland exports is on track to reach the lowest level since 1984, when digital timepieces were in vogue and Swatch Group AG had just been formed in reaction to low-cost competition. Three decades later, difficult times are back: 11-month data is due Tuesday after the value of Switzerland’s watch exports dropped 11 percent in the first 10 months of the year. While brands like Vacheron Constantin, Cartier and Vulcain cut jobs, Swatch has held back on any such announcements even as costs mount.