About: http://webisa.webdatacommons.org/238822970

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Each level is more demanding than the previous one and is a mixture of short-term and long-term improvements or achievements.
http://www.w3.org/ns/prov#wasQuotedFrom	aviationpros.com