When a person is convicted of sexual battery in violation of § 18.2-67.4, attempted sexual battery in violation of subsection C of § 18.2-67.5, a violation of § 18.2-371 involving consensual intercourse, anal intercourse, cunnilingus, fellatio, or anilingus with a child, indecent exposure of himself or procuring another to expose himself in violation of § 18.2-387, or a violation of § 18.2-130, and it is alleged in the warrant, information, or indictment on which the person is convicted and found by the court or jury trying the case that the person has previously been convicted within the 10-year period immediately preceding the offense charged of two or more of the offenses specified in this section, each such offense occurring on a different date, he is guilty of a Class 6 felony.