UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ____________________________________ FORM 20-F ____________________________________ ¨ REGISTRATION STATEMENT PURSUANT TO SECTIONS 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR þ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ¨ SHELL COMPANY REPORT PURS ...