The Census Bureau is increasing the number of telephone help lines, after receiving nearly 50,000 calls over the weekend, the agency said Tuesday. The toll-free service for people with questions about the census opened Friday with 390 lines available. The total is now being increased to 460 lines. Lines for Spanish-speaking callers were a particular problem, officials said, and they are being increased from 88 to 160. ``The volume of calls we're receiving means there is a high degree of awareness and support for the census. But obviously we don't want people to get a busy signal when they call and we're taking steps to make sure that they don't,'' said census director Barbara Everitt Bryant. The assistance lines are staffed from 9 a.m. to 9 p.m., local time, seven days a week. The numbers are: English: 1-800-999-1990. Spanish: 1-800-283-6826. Cambodian: 1-800-289-1960. Chinese: 1-800-365-2101. Korean: 1-800-444-6205. Laotian: 1-800-888-3208. Vietnamese: 1-800-937-1953. Thai: 1-800-288-1984. Hearing Impaired: 1-800-777-0978.