We have a nightly job that uses sql loader to insert data from a csv file. Here is a small sample of the data:

```
select * from ktimov.press_schd order by job;

PLANT JOB EST_COMPLETION INSERT_DATE
10    111 6/26/2017      5/10/2017
10    111 7/1/2017       5/11/2017
10    111 7/5/2017       5/12/2017
10    222 6/20/2017      5/10/2017
10    222 6/26/2017      5/11/2017
10    333 7/26/2017      5/10/2017
10    333 6/30/2017      5/11/2017
10    333 8/10/2017      5/12/2017
10    333 8/6/2017       5/13/2017
10    333 8/7/2017       5/14/2017

```

`INSERT_DATE` is default sysdate of when the record was inserted.  

`EST_COMPLETION` is an estimate of when the JOB will be completed. So for example:

On 5/10/17, JOB# 111 was estimated to be completed by 6/26. Then on 5/11 the estimated completion was changed to 7/1.

I'm looking to query this data to show the following:

JOB#, First EST Date, Last Est date, Count of how many times it was changed.

The end result should be like this:

```
JOB FIRST_DATE LAST DATE Count_Changes
111 6/26/2017  7/5/2017  3
222 6/20/2017  6/26/2017 2
333 7/26/2017  8/7/2017  5

```

Any ideas how I can accomplish this?