KJV - Thou hast multiplied the nation, and not increased the joy: they joy before thee according to the joy in harvest, and as men rejoice when they divide the spoil.

ASV - Thou hast multiplied the nation, thou hast increased their joy: they joy before thee according to the joy in harvest, as men rejoice when they divide the spoil.

BBE - You have made them very glad, increasing their joy. They are glad before you as men are glad in the time of getting in the grain, or when they make division of the goods taken in war.

WEB - You have multiplied the nation, you have increased their joy: they joy before you according to the joy in harvest, as men rejoice when they divide the spoil.

YLT - Thou hast multiplied the nation, Thou hast made great its joy, They have joyed before Thee as the joy in harvest, As `men' rejoice in their apportioning spoil.

DARBY - Thou hast multiplied the nation, hast increased its joy: they joy before thee like to the joy in harvest; as [men] rejoice when they divide the spoil.

DRA - Thou hast multiplied the nation, and hast not increased the joy. They shall rejoice before thee, as they that rejoice in the harvest, as conquerors rejoice after taking a prey, when they divide the spoils.

Notes

There is some debate if the word "Not" should be here like the KJV has it.

Based on my study it looks like in the Hebrew text there is a homophone. (Words that sound the same but have different meanings. Like in English "to", "too", and "two".)

The word in Hebrew can mean "not" or "to him" or "his".