Complex sentence: During the second half of the 20th century, there was a steady decline in the importance of manufacturing and the economy of the United Kingdom shifted toward services although manufacturing remains important for overseas trade and accounted for 44% of goods exports in 2014.
Split into simpler sentences: During the second half of the 20th century, there was a steady decline in the importance of manufacturing and the economy of the United Kingdom shifted toward services. Although manufacturing remains important for overseas trade and accounted for 44% of goods exports in 2014.