DETROIT // The full scale of how tough last year was for Detroit's Big Three will be revealed next week, when the cumulative car sales figures for 2009 are announced in the US. The year's statistics are expected to show US sales to have slumped to a little over 10m vehicles, significantly below the decade's historical average of more than 16m vehicles. With sales data already collected from the first 11 months of 2009, the figures also confirm two of the Detroit three lost further market share in a rapidly declining market. GM fell back 2.3 per cent to 19.8, while Chrysler also lost 2 per cent to stumble back to 9 per cent up to the end of November 2009. However, Ford increased its reach by a point to 15.9 per cent, helped in part by its popular Ford F-Series truck maintaining its position at the top of the national sales charts. The car maker's Fusion saloon also ranked in the top 10 of sales to the end of November, alongside the Chevrolet Silverado, the Dodge Ram, three Hondas (Accord, Civic and CR-V), two Toyotas (Corolla and Camry) and the Nissan Altima.