Del. Code tit. 6, §§ 17-1206

Limited partners of a statutory public benefit limited partnership or assignees of partnership interests in a statutory public benefit limited partnership owning individually or collectively, as of the date of instituting such derivative suit, at least 2% of the then-current percentage or other interest in the profits of the limited partnership or, in the case of a limited partnership with partnership interests listed on a national securities exchange, the lesser of such percentage or partnership interests of at least $2,000,000 in market value, may maintain a derivative lawsuit to enforce the requirements set forth in § 17-1204(a) of this title.