number of robotic  vacuum cleaners sold
World Robotics 2015 Service Robots. The total number of professional service robots sold in 2014 rose by a solid 11.5% compared to 2013 to 24,207 units up from 21,712 in 2013. The sales value slightly increased by 3% to US$3.77 billion. Since 1998, a total of about 172,000 service robots for professional use have been counted in these statistics.