Confusion has arisen as to how the locking of turnstiles at Metro Rail stations has affected ridership numbers. A survey by the Los Angeles Times determined that the turnstiles have reduced as many as 800,000 monthly boardings, to 4 million boardings a month. Currently, Metro does not use turnstiles to count boardings as other agencies do. Instead, Metro relies on staff counting a sample of passengers at stations, then interpolating the data according to the time of day and adding seasonal adjustments. However, turnstile and sample counts have differed greatly, with turnstile numbers much higher than what was sampled, and vice versa. Metro depends on these counts to receive federal funds and hope that turnstile counts can be incorporated to ridership numbers in the future.