csv. number Data-driven scroll animation

First, I had to alter your csv file so that the numbers aren't such large integers. My test file (test3.csv), has converted the numbers to billions and looks like this:

Date,Elon Musk,Mark Zuckerberg
1/1/2010,0.8,4
1/2/2010,0.801643836,4.01586369
1/3/2010,0.803287671,4.03172738
1/4/2010,0.804931507,4.047591069
1/5/2010,0.806575342,4.063454759
1/6/2010,0.808219178,4.079318449
1/7/2010,0.809863014,4.095182139
1/8/2010,0.811506849,4.111045828
1/9/2010,0.813150685,4.126909518
1/10/2010,0.814794521,4.142773208
1/11/2010,0.816438356,4.158636898

I imported test3.csv and dropped it into my test comp as a layer so that the expressions have easy access to the number of rows of data.

I used this expression for layer v1:

period = 2; // update date every x seconds
n = thisComp.layer("test3.csv")("Data")("Number of Rows");
i = Math.min(Math.floor(time/period),n-1);
footage("test3.csv").dataValue([0,i])

This for v2:

period = 2; // update date every x seconds
n = thisComp.layer("test3.csv")("Data")("Number of Rows");
i = Math.floor(time/period);
if (i < n-1){
  cur = footage("test3.csv").dataValue([1,i]);
  next = footage("test3.csv").dataValue([1,i+1]);
  t = time%period
  val = linear(t,0,period,cur,next);
}else{
  val = footage("test3.csv").dataValue([1,n-1]);
}
Math.round(val*1000000000)

This for v3:

period = 2; // update date every x seconds
n = thisComp.layer("test3.csv")("Data")("Number of Rows");
i = Math.floor(time/period);
if (i < n-1){
  cur = footage("test3.csv").dataValue([2,i]);
  next = footage("test3.csv").dataValue([2,i+1]);
  t = time%period
  val = linear(t,0,period,cur,next);
}else{
  val = footage("test3.csv").dataValue([2,n-1]);
}
Math.round(val*1000000000)

and this for v4:

v2 = thisComp.layer("v2").text.sourceText;
v3 = thisComp.layer("v3").text.sourceText;
Number(v2) - Number(v3)

That should get you close.