there have been
is it possible to say something like:
There have been making a lot of improvements in this sphere for last decades.
or
There have done a lot of improvements in this sphere for last decades.
or
There were a lot of improvements in this sphere last decades.

How to say it propertly?

Question

there have been
is it possible to say something like:
There have been making a lot of improvements in this sphere for last decades.
or
There have done a lot of improvements in this sphere  for last decades.
or
There were a lot of improvements in this sphere last decades.

How to say it propertly?

Answer

There have been a lot of improvements made in this sphere over the last decades.

or

A lot of improvements have been made in this sphere over the last decades.