The best way to calculate the aggregate risk from a single client is to examine all of the individual agreements made between the two parties and calculate them separately. In such a case, the concept of diminishing returns must be considered, because the cost of these individual assessments and the time required to complete them should not be prohibitively expensive.
Furthermore, the risks associated with each agreement should be clearly defined in these calculations, and their impact on the overall risk assessment should be noted. There will always be some level of uncertainty, and global events that affect the economy cannot always be predicted.

To calculate aggregate risk, follow these steps:

1. Identify Risks: List all potential risks associated with the project or activity.
2. Assess Individual Risks: Evaluate the probability and impact of each risk, often using a risk matrix.
3. Quantify Risks: Assign numerical values to the probability and impact, typically on a scale of 1 to 5 or using percentages and financial values.
4. Aggregate Risk Calculation: Use methods like Expected Monetary Value (EMV), which multiplies the probability of each risk by its impact and sums these values for all risks.
5. Adjust for Correlation: Consider the correlation between risks to avoid overestimation or underestimation.
6. Risk Mitigation and Reassessment: Implement mitigation strategies and reassess the overall risk.

This comprehensive approach ensures a thorough understanding of total risk exposure.