The consumer confidence index worsened to 49.8 in May from 50.0 in April, the first fall in two months, the Cabinet Office said. The April reading was the best level for the index since June 1990 when it stood at 50.3, the government said. The consumer confidence index is based on replies to a survey asking about four aspects of consumer sentiment: perception of general economic well-being, income growth, employment conditions and willingness to purchase durable goods. Respondents are asked if there has been improvement in these areas compared to three months earlier. Numbers above 50 mean that respondents reporting improvement outnumber those seeing deterioration. Figures below 50 mean the majority believe conditions have worsened. The sub-index for general economic well-being fell to 46.7 from 47.0 in April, while the income growth sub-index increased to 46.3 from 46.2. The employment conditions sub-index dropped to 54.9 from 55.2 and the sub-index for willingness to buy durable goods edged down to 51.2 from 51.6.