CONSUMERS on the mainland are absorbing almost half of total goods shipped from Hongkong, with just 52 per cent of the territory's China-bound exports being marked up for outward processing last year, according to government statistics. By the fourth quarter the proportion was down to 48 per cent. The annual figure compares with 55 per cent in the previous year. Outward processing, or partial assembly, is defined as the export of raw materials and semi-finished goods for processing and subsequent re-import to the country of origin. As such, these shipments are distinguished from finished goods snapped up by consumers and traders in China. Once processed, the goods will be sent back to the venture for finishing and packaging before returning to Hongkong for sale as finished goods. Splitting up Hongkong's total exports, some 74 per cent of China-bound domestic exports were destined for outward processing while the figure for re-exports was 46 per cent. Conversely, 72 per cent of Hongkong's imports from China were related to outward processing. Over the same period, 78 per cent of Hongkong's re-exports of China origin to the rest of the world - stripping out China - were produced through outward processing in China. A spokesman for the Government said: ''The decreases in the proportion of exports to China for outward processing as recorded in 1992 reflect that Hongkong's exports for meeting domestic demand in China - exports to China not destined for outward processing - increased at a faster pace than outward processing trade during the period. ''This is in line with the sustained increase in domestic demand in China for imported goods.'' In value terms $141.64 billion of Hongkong's total exports to China in 1992 were for outward processing, representing an increase of 24 per cent over 1991. Over the same period the value of imports from China related to outward processing rose 29 per cent to $254.01 billion. Of Hongkong's re-exports of China origin to the world, the value increased 35 per cent to $299.83 billion.