London is a major hub for global companies and careers, with one-fourth of the top 500 global companies based there. It accounts for 23.7% of the UK's total economic output and has a highly educated workforce, with 40% of working-age Londoners holding a higher education qualification compared to 30% nationally. However, two-thirds of London firms reported difficulty recruiting highly skilled staff. The number of jobs and employees in London has grown substantially in recent years, particularly in professional, scientific, technical, administrative, and support service fields.