Most have entered the business in the last few years.
John entered his father's business when he returned in 1859.
He has sold $32 million of them since entering the business in 1994.
Those who've entered the business since the mid-90's have never seen a down cycle.
Another possibility is that other American companies will enter the business.
The couple entered the business even though both of them had professional degrees.
The President's children followed a common pattern in entering business.
He never thought about entering his father's business for at least one odd reason.
But that could change if big Japanese companies decide to enter the business.
He entered business as a real estate agent at the age of 22.