9.    GOODWILL

Goodwill represents the excess of the purchase price over the fair value of net assets of businesses acquired. The carrying amount of goodwill was $368.5 million at December 31, 2018 and $346.5 million as of December 31, 2017. Goodwill increased for the year ended December 31, 2018 due primarily to acquisitions, partially offset by currency conversion of foreign goodwill. The carrying amount of goodwill in foreign countries was $54.9 million as of December 31, 2018 and $46.3 million as of December 31, 2017. The changes in the carrying amount of goodwill for the twelve months ended December 31, 2018 and 2017 are as follows: