Statistics presented in the form of chart By state of conservationBy subjectBy visible feature Continents ▾ Country ▾ Centuries ▾ Reset Continents ▾ Country ▾ Centuries ▾ Reset i This graph illustrates the proportion of maps on which various features are visible. For example, it shows the percentage of maps on which roads or natural areas are visible. Continents ▾ Country ▾ Centuries ▾ Reset