Sentence:  Boys 32 , 23 , 31 , 17 , 30 , 19 , and 24 had `` same schedule '' at Onset and Completion ; thus early forecasting of the pubescent <WSD>stage</WSD> would appear possible for only seven boys . 
Meaning of the word marked with <WSD> tags:  a specific identifiable position in a continuum or series or especially in a process