From 1997–2013, the value added by private construction industry as percentage of national GDP declined from high of 6.14% (in 1997 and 1998) to low of 3.69% in 2011 and then rose to still-too-low 3.73% in 2013. Although this is an accurate look at the sector, it understates impact of construction industry on economy. Because these numbers are based on value added measure, they don't include demand for building materials, transportation services, financial services, or sales and leasing.