Try this. Start with your string of text and apply a Scale Animator and set the Scale value to 0,0. Add an Expression Selector and delete the Range Selector. Replace the expression in the Expression Selector’s Amount property with this:
rampUp = .5;
rampDn = .5;
delay = .25;
myDelay = (textIndex-1)*delay;
t = time - (inPoint + myDelay);
if (t < rampUp)
linear(t,0,rampUp,100,-50)
else
linear(t,rampUp,rampUp+rampDn,-50,0);
Adjust the rampUp, rampDn, and delay variables to suit your needs.