weighted average number of common shares and potential dilutive common equivalents 149614 149393 155877 ( 1 ) excludes the effect of outstanding stock options , as well as the exchangeable senior notes ( 201cexchangeable notes 201d ) issued in 2006 , that have an anti-dilutive effect on earnings per share for the periods presented . a joint venture partner in one of our unconsolidated companies has the option to convert a portion of its ownership in the joint venture to our common shares