Average rent in San Francisco jumped 19% this year.

“Priceonomics puts the median price of a San Francisco apartment renting today at $3,600, up from $3,023 last year. Studios are fetching $2,300, one-bedrooms come in at $3,120, the median two-bedroom costs $4,000, and three-bedrooms are going for $4,795.”
http://sf.curbed.com/archives/2014/08/14/colorcoding_san_franciscos_totally_bonkers_rental_market.php

Rent Prices Are Going Up, But Your Income Isn't. Original chart with data source: http://www.motherjones.com/politics/2014/06/rental-affordability-crisis-hud
Rent Prices Are Going Up, But Your Income Isn’t. Original chart with data source: http://www.motherjones.com/politics/2014/06/rental-affordability-crisis-hud

The numbers are a good indicator of why any eviction from a rent-controlled unit today is also an eviction from San Francisco entirely: prices are just too damn high to find a new apartment at a comparable rate.
http://www.sfbg.com/politics/2014/08/13/san-francisco-rent-explosion-median-rent-two-bedroom-apartment-tops-4k

It’s a national problem: the foreclosure crisis made former owners into renters, the federal government cut housing assistance, and now more than 28% of Americans pay more than half of their salaries for rent.
Mother Jones: National Data on Rising Rents
http://www.motherjones.com/politics/2014/06/rental-affordability-crisis-hud