expression chop change $V to older value

Hello,

I use the join chop to transform the information of velocity to apply that to instancing in geo comp.

I would want that the values stays in position until the next value.
But, after every note the velocity return to 0.

At present, I use chop expression to transform the value 0 into 0.5

if($V==0,0.5,$V)

It is not very effective.

Is there a way to make it?

Thank you
Julien.

P.S : Sorry for my English.
I hope that it is easy to understand.
velocityforinstance.toe (6.51 KB)