A credit supervisor within the counterparty risk department of a leading financial institution utilizes a simplified version of the Merton model to assess the relative vulnerability of its largest counterparties to changes in their value and financial stability. To assess the default risk of three specific counterparties, the supervisor calculates the distance to default over a 1-year horizon (t=1). The companies under consideration, named Company P, Company Q, and Company R, are in the same industry and do not distribute dividends. The pertinent details about these companies are summarized in the following table:

Company	P	Q	R
Market value of assets (EUR million)	100	150	250
Face value of debt (EUR million)	60	100	160
Annual volatility of asset values	10.0%	7.0%	8.0%

Based on the provided data, and considering that each company's only financial liability is a zero-coupon bond maturing in 1 year, together with the approximation formula for the distance to default, what is the correct ranking of the counterparties from the highest to the lowest probability of default?