(29.6% in 2017, compared to 22.4% in the EU). The risk of poverty or social exclusion in rural areas is nearly double that of urban areas, which corresponds to the gap in the unemployment rate between cities and rural areas (4.5% versus 11% in 2017). In particular the metropolitan areas of Vilnius and Kaunas, where significant economic activity is centred, drive a significant gap between AROPE rates in urban and rural areas. In 2017, the AROPE rate in rural areas was 37.2%, compared to 19.9% in cities. Over the past 15 years, Lithuania has experienced the fastest convergence in the EU, but the benefits of economic growth are uneven across regions. Disparities among Lithuania's regions have steadily grown in this period. While GDP per capita reached nearly 110% of the EU average in the capital region of Vilnius, it is only between 42% and 77% in other regions. The country's rapid convergence is mainly fuelled by two regions – the capital region of Vilnius and Kaunas County – producing 42% and 20% of the national GDP, respectively. In 2014–2016 these regions grew on average by 4.6% (Vilnius) and 3.3% (Kaunas), while the other regions, which have a higher share of rural areas, stagnated or were in recession. The supply of new housing in Vilnius and its suburbs, the country's biggest real estate market, has reached post-crisis highs and the stock of unsold apartments in the three largest cities has started to increase since the beginning of 2017. The demand for housing is still strong, fuelled by rapidly rising wages, benign financial conditions and positive expectations. In the first half of 2018, the number of monthly transactions was the highest since the 2007–2008 peak. Most foreign direct investment and productive public investment in Lithuania is concentrated around the two main economic development poles of Vilnius and Kaunas. Vilnius Industrial Park is located 18.5 kilometres from the city and its land is intended for commercial, industrial use. Science and research In 1675, Tito Livio Burattini lived in Vilnius and published a book Misura universale in which he suggested to use term metre for a unit of length for the first time. In 1753, on the initiative of Thomas Zebrowski the Vilnius University Astronomical Observatory was established, which was among the first observatories in Europe and the first in the Polish-Lithuanian Commonwealth. Marcin Odlanicki Poczobutt led the reconstruction of the observatory in 1770–72