Washington: The U.S. Citizenship and Immigration Services has received about 22,000 petitions for the much sought after H-1B work visas in the first four days after it started accepting applications on April 2, officials said. "We have received approximately 22,000 H-1B petitions for the fiscal 2013 beginning October 1 this year," U.S. Citizenship and Immigration Services (USCIS) spokesperson Bill Wright told PTI. The USCIS official, however, was quick to note that these are preliminary figures. The 22,000 H-1B petitions received in the first four days are from both the categories: Congressionally mandated cap of 65,000 in the general category and another 20,000 in the advance degree category. Even these preliminary figures indicate that there has been quite an increase in the H-1B petitions this year as compared to the previous two years, it is much less than the previous years when the cap was reached on the very first day. In 2011, in the first week, the USCIS had received approximately 5,900 H-1B petitions counting toward the 65,000 cap, and approximately 4,500 petitions toward the 20,000 cap exemption for individuals with advanced degrees. In 2010, USCIS had received only 13,500 petitions in the Congressionally mandated cap of 65,000 in the first week and approximately 5,600 petitions for individuals with advanced degree. USCIS, in 2009, had received 42,000 H-1B applications under the Congressional mandated quota of 65,000 in the first week. In the advanced degree category it received about similar number of applications. U.S. businesses use the H-1B programme to employ foreign workers in speciality occupations that require theoretical or technical expertise in specialised fields, such as scientists, engineers, or computer programmers.