Complex sentence: Spain enjoyed the second world highest growth rate just after Japan and became the ninth largest economy in the world, just after Canada, and the country left behind two centuries of poverty and endemic underdevelopment since the loss of Spanish Empire at the beginning of 19th century.
Split into simpler sentences: Spain enjoyed the second highest growth rate in the world, just after Japan, and became the ninth largest economy in the world, just after Canada. Spain joined the industrialized world, leaving behind the poverty and endemic underdevelopment it had experienced since the loss of the Spanish Empire at the beginning of the 19th century.