Conversation so far:
what did diamond do in the 90s
During the 1990s, Diamond produced six studio albums.
Name one of Neil Diamond's albums during the 1990s.
The Christmas Album is the twentieth studio album by Neil Diamond and his first to feature Christmas music.
Were Neil Diamond's albums, in particular The Christmas Album during the 1990s a hit?
As of November 2014, it is the twenty-fifth best-selling Christmas/holiday album in the United States during the SoundScan era of music sales tracking, having sold 1,910,000 copies.

Question: what was the highest they reached
Self-contained rewrite: What was the highest Neil Diamond's albums reached in terms of sales?