$109,703.86 per year average income.
The gross domestic product for 2012 was $15684.80 billion.
There were 142,974,000 people employed.
So, the average income should be $109,703.86 per year.
That is exactly what it should be.
So, that would be the "fair share" number. $109,703.86 per year average income.
What definition of 'fair' does that fit? That everyone should be alotted the same amount of money regardless of their contribution? That meets no definition of fair I've ever heard.