Number of cities where fast food and other low-wage workers went on strike this week to demand a $15 minimum hourly wage and the right to form a union: 190

Year in which the Fight for 15 movement began as a strategy to address growing income inequality: 2012

Year in which fast food strikers were joined by home health aides and other service workers including airport baggage handlers and dollar store employees: 2014

Since the strikes began, number of cities that have passed ordinances raising the local minimum wage above the federal minimum of $7.25 an hour: 18

Number of other cities that are considering raising their minimum wage: 5

Hourly wage to which Washington, D.C. will raise its minimum wage by 2016: $11.50

Minimum hourly wage Louisville is considering: $10

Level to which President Obama raised the minimum hourly wage for federal contractors earlier this year: $10.10

The 1968 minimum wage, in today's dollars: $10.95

Percent of fast food workers that receive some form of public assistance: 52

Hourly wage now earned by three-time striker Steven Wilkerson, an Iraq War vet who works at a combination Dunkin' Donuts, Quizno's and Godfather's Pizza in a Hess gas station in Tampa, and who credits his recent promotion and expected raise to his involvement in the protests: $8.50

The average hourly pay for restaurant workers in 2013: $8.74

Year in which San Francisco raised its minimum wage to $10.74: 2003

Minimum hourly wage the city has since voted to phase in: $15

According to a recent study of San Francisco's minimum wage law, percentage points by which private sector employment there outpaced other Bay Area counties that didn't enact a higher local wage in the eight years after the law was passed: 10

According to a 2010 study of almost 300 neighboring U.S. counties with different minimum wage rates, drop in employment that results from enacting a higher minimum wage: 0