Ten people with different incomes have applied for membership in an exclusive club. One of the club's criteria in deciding whom to accept is to favor those applicants whose incomes are high relative to other applicants'. Each applicant knows his own income and can reveal it voluntarily by submitting his income tax returns. Also, everyone happens to know that there is exactly one applicant whose income is $10,000, one whose income is $20,000, and so forth up to $100,000. How many applicants reveal their incomes?