The dates 1906-1924 cover a time of significant change in passenger travel conditions, so you'll find many different accounts. By 1906 newer ships were already constructed or re-fitted to have "third" or "tourist" class instead of steerage. Tourist class typically meant a small cabin (often with toilet/sink) on the lower decks, basic dining room, etc. Also the passage usually lasted only 5-12 days, depending on the departure/arrival ports' distance. Their ticket price included meals.
By 1909 the comparison of the new ships to the old probably explains an explosion of news articles complaining of the "horrific" conditions in steerage. If you read them you may find those stories relate to specific ships, or shipping lines, that are no longer meeting standard expectations for transatlantic travel.
My point is it may be easier to answer your question regarding the majority of passengers who sailed on a specific steamship line, or from a specific departure port, since those passengers would all share a more similar experience (though I'm sure it changed over time even within those parameters).