PHP：根据foreach循环中另一个变量的变化增加变量

I have a foreach loop that prints the history of line item changes in my application. Each line item has a number, and each line item can have multiple changes.

What I want to do is display the line number alongside each change when my loop executes. $i will hold the line number.

$i = 1;
foreach($lineItem as $line) {
   echo $i; //line number
   echo $line['field_changed'];
   echo $line['change_date'];
   echo $line['change_from'];
   echo $line['change_to'];
}

The code reads from a DB table called line_item_changes with the following structure:

id  line_id  parent_id
--  -------  ---------
1   2401     521
2   2401     521
3   2401     521
4   2500     521
5   2502     521
6   2502     521  

I want to increment $i every time the value in $line['line_id'] changes. So that, when the results display, they look something like this:

Line #: 1
field: notes
date: 10/9/2018
from: test
to: test2

Line #: 1
field: quantity
date: 10/1/2018
from: 4
to: 3

Line #: 2
field: need_date
date: 10/1/2018
from: 10/24/2018
to: 10/27/2018

etc.