Highest averages & largest remainders allocating seats methods and
    several party system scores.
    Implemented highest averages allocating seats methods are D'Hondt, Webster,
    Danish, Imperiali, Hill-Huntington, Dean, Modified Sainte-Lague,
    equal proportions and Adams.
    Implemented largest remainders allocating seats methods are Hare, Droop,
    Hangenbach-Bischoff, Imperial, modified Imperial and quotas & remainders.
    The main advantage of this package is that ties are always reported
    and not incorrectly allocated.
    Party system scores provided are competitiveness, concentration,
    effective number of parties, party nationalization score,
    party system nationalization score and volatility.
    References:
    Gallagher (1991) <doi:10.1016/0261-3794(91)90004-C>.
    Norris (2004, ISBN:0-521-82977-1).
    Consejo Nacional Electoral del Ecuador (2014)<http://cne.gob.ec/documents/Estadisticas/Atlas/ATLAS/CAPITULO%206%20web.pdf>.
    Laakso & Taagepera (1979) <https://journals.sagepub.com/doi/pdf/10.1177/001041407901200101>.
    Jones & Mainwaring (2003) <https://kellogg.nd.edu/sites/default/files/old_files/documents/304_0.pdf>.
    Pedersen (1979) <https://janda.org/c24/Readings/Pedersen/Pedersen.htm>.
    Golosov (2010) <https://ppq.sagepub.com/content/16/2/171.abstract>.
    Golosov (2014) <https://ppq.sagepub.com/content/early/2014/09/08/1354068814549342.abstract>.

Several web services are available that provide access to elevation
             data. This package provides access to many of those services and 
             returns elevation data either as an 'sf' simple features object 
             from point elevation services or as a 'raster' object from raster 
             elevation services. In future versions, 'elevatr' will drop 
             support for 'raster' and will instead return 'terra' objects. 
             Currently, the package supports access to the Amazon Web Services 
             Terrain Tiles <https://registry.opendata.aws/terrain-tiles/>, 
             the Open Topography Global Datasets 
             API <https://opentopography.org/developers/>, and the USGS 
             Elevation Point Query Service <https://apps.nationalmap.gov/epqs/>.