Fig. 2From: Radiological research activity 1998–2007: relationship to gross domestic product, health expenditure and public expenditure on educationTrend of the cumulative impact factor (IF) per capita (p.c.) between 1998 and 2007 shown separately for different groups of gross domestic product (GDP) per capita. Switzerland, followed by the Netherlands and Belgium, had the highest cumulative IFs per capita from 1998 to 2007Back to article page