The three most prominent pieces of law protecting individuals from gender discrimination in the United States are the Equal Pay Act of 1963, the Civil Rights Act of 1964 Title VII, and the Pregnancy Discrimination Act. Furthermore, every state law code contains further protections for individuals, regardless of their sex or gender. However, as most individuals realize and studies show, gender discrimination still rampantly exists in the workplace foremost. For example, nearly ninety-five percent of corporate executives in Fortune 100 companies are males. These disparate numbers show a relatively prominent level of gender discrimination probably occurring in the American workforce, however, under the laws, not all individuals are protected in all circumstances. For example, the Equal Pay Act mandates equal pay for equal work done by women. "Equal work", however, is a determined by a litany of variable factors, including the exact nature of the work performed, the responsibility level of each person, the past working experience, the educational background, the starting salaries accepted by workers, and the performance. Proving all these factors as being equal between one male and one female worker are virtually impossible to prove, especially within one given company. Hence, many cases of pseudo-sex discrimination continually occur on a technical basis in the American workforce.