In Russell v. Russell, 157 Vt. 295, 299, 597 A.2d 798, 800 (1991), the Court held that the date of separation of the parties should be used for the purpose of determining what proportion of a pension should be subject to the claims of an employee's former spouse, because the date of separation "is most reflective of the functional end of marriage and will be a relatively easy benchmark to determine." Id. The parties in Russell had agreed to distribute the husband's pension between them when it came due, rather than to assign a monetary value to the pension at the time of the final hearing and subject this value to equitable distribution. Id. As the Court explained in Russell, when a court apportions a pension between parties to a divorce, it "must apply a coverture fraction to reflect the proportion of the entire pension attributable to the marriage." Id. The coverture fraction reflects the proportion of the entire pension attributable to the marriage. Id.