A sentence has been split up into segments and given below in jumbled order. While the first and the last segments of the sentence (1 and 6) are in the correct order, the segments in between are jumbled up. Arrange the segments in the correct order to form a meaningful and coherent sentence.

1) An outstanding feature of the 21st century has been

P) greater security and education which

Q) the improvement of the income and

R) living conditions of the

S) working man leading to

6) has meant greater political power