Here is how this graph was done:
Graph > Scatterplot, with Regression > Y variables= Longjump_Men, X variables=Year_Men, Labels > Change Title.
Click on line, right-click and select Edit Line, change thichness to 3.
Remove row 1 with "1896" from worksheet, make new column "x" with 1900 2008, Stat > Regression > Regression, Response= Longjump_Men, Predictors=Year_Men, Options > Prediction Intervals for new Observations > x, check Store Fits
click inside graph, right-click, choose Add > Calculated Line, Y variable: PFIT1, X variable: x. Click on line, right-click and select Edit Line, change thickness and color
Remove row with "1968" and repeat above
Remove all rows before "1984", change "x" to 1984 2008, and repeat above
Click on the line icon above the graph, draw short line in upper left corner, select line, change thickness. Click on T icon, add text next to line, change font size to 8.
Repeat for other lines
Click on box icon, draw box around legend, select box, right-click, choose Edit Rectangle, Custom Type: N