Income differences in China since the 1950s have been much smaller than in most other countries.[1] There was never any attempt, however, at complete equalization, and a wide range of income levels remained.[1] Income differences grew even wider in the 1980s as the economic reform policies opened up new income opportunities.[1] More than two-thirds of all urban workers were employed in state-owned units, which used an eight-grade wage system.[1] The pay for each grade differed from one industry to another, but generally workers in the most senior grades earned about three times as much as beginning workers, senior managers could earn half again as much as senior workers, and engineers could earn twice as much as senior workers.[1] In 1985 the average annual income of people employed in state-owned units was ¥1,213.[1] An important component of workers' pay was made up of bonuses and subsidies.[1] In 1985 bonuses contributed 13 percent of the incomes of workers in state-owned units; subsidies for transportation, food, and clothing added another 15 percent.[1] One of the most important subsidies – one that did not appear in the income figures – was for housing, nearly all of which was owned and allocated by the work unit and rented to unit members at prices well below real value.[1] In 1985 urban consumers spent just over 1 percent of their incomes on housing.[1]