Diversity is one of the core strengths of the Group and insulates us from much seasonal and cyclical demand. We serve a very wide range of industries and have a great diversity of end markets and customers. During 2018, our largest industry sector (Food), accounted for 17% of sales and no single customer in any industry accounted for sales of greater than 1% of the Group total. We have an excellent balance between higher-growth end markets and those that are more "defensive" and less cyclical. Approximately 50% of Group revenue is derived from these defensive end markets, such as: Food & Beverage, Pharmaceutical & Biotechnology, and Healthcare.
To maintain operational efficiency, production output and product quality, regular maintenance spending is required by our end users; approximately 50% of Group revenue is derived from maintenance and repair sales, supported by our end users' opex budgets. Small project sales, which improve existing systems and are supported by our end users' opex budgets, account for 35% of Group revenue. Large project sales, that build new systems and are supported by our end-users' capex budgets, account for approximately 15% of Group revenue.