"To ascertain whether a statute should be applied retroactively, legislative intent is the 'paramount' consideration." (People v. Nasalga (1996) 12 Cal.4th 784, 792.) Whether the Legislature intended a statute to operate retroactively is a question of law that we decide independently. (In re Chavez (2004) 114 Cal.App.4th 989, 994 8 Cal. Rptr. 3d 395.) The California high court has explained principles of retroactivity in statutory construction as follows: "Generally, statutes operate prospectively only. In the words of section 3 of California's Civil Code: 'No part of this code is retroactive, unless expressly so declared.' . . . The Court explained in Evangelatos v. Superior Court (1988) 44 Cal.3d 1188, 1207: '"'The first rule of statutory construction is that legislation must be considered as addressed to the future, not to the past. . . . The rule has been expressed in varying degrees of strength but always of one import, that a retrospective operation will not be given to a statute which interferes with antecedent rights . . . unless such be "the unequivocal and inflexible import of the terms, and the manifest intention of the legislature."'"'In the words of the United States Supreme Court, 'the "principle that the legal effect of conduct should ordinarily be assessed under the law that existed when the conduct took place has timeless and universal appeal."' " (Myers v. Philip Morris Companies, Inc. (2002) 28 Cal.4th 828, 840-841.) And "'a statute that is ambiguous with respect to retroactive application is construed . . . to be unambiguously prospective.' " (Id. at p. 841.) In In re Estrada (1965) 63 Cal.2d 740, the court explained: "Section 3 simply embodies the general rule of construction, coming to us from the common law, that when there is nothing to indicate a contrary intent in a statute it will be presumed that the Legislature intended the statute to operate prospectively and not retroactively. That rule of construction, however, is not a straitjacket. Where the Legislature has not set forth in so many words what it intended, the rule of construction should not be followed blindly in complete disregard of factors that may give a clue to the legislative intent." (Estrada, supra, 63 Cal.2d at p. 746.) The court emphasized that section 3 "is to be applied only after, considering all pertinent factors, it is determined that it is impossible to ascertain the legislative intent." (Estrada, at p. 746.) In considering an amendment reducing the penalty for a prison escape, the court concluded "the Legislature must have intended that the amendatory statute should operate in all cases not reduced to final judgment at the time of its passage." (Ibid.) The court reasoned: "When the Legislature amends a statute so as to lessen the punishment, it has obviously expressly determined that its former penalty was too severe and that a lighter punishment is proper as punishment for the commission of the prohibited act. It is an inevitable inference that the Legislature must have intended that the new statute imposing the new lighter penalty now deemed to be sufficient should apply to every case to which it constitutionally could apply." (Id. at p. 745.) In other words, " 'a legislative mitigation of the penalty for a particular crime represents a legislative judgment that the lesser penalty or the different treatment is sufficient to meet the legitimate ends of the criminal law ... ,' " and when a lesser penalty has been deemed sufficient to satisfy the public interest, the Legislature obviously intends that no prisoner remain subject to the original, greater penalty. (Ibid.)