Last year, the per capita income of Longmen Village was 2,800 yuan. With the support of the central government's policy of building a new socialist countryside, the per capita income this year is 4,200 yuan. By what percentage has the per capita income of Longmen Village increased?
龙门村去年人均收入2800元，在中央建设社会主义新农村的政策支持下，今年人均收入4200元．龙门村人均收入增加了百分之几？
<gadget id="calculator">4_200 - 2_800</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 / 2_800</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>