Looking on the internet deeply has found these results:

I will read your report when I have a spare time is the most popular phrase on the web.

I will read your report when I have a spare minute 172,400,000 results on the web	I will read your report when I have a spare time 14,980,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I will... Leave here and I will read your material. I realized that I owed him a lot. I will leave here, and I will read your material. But I will read your manuscript today, even if they fire me. Rest assured I will read your proposal and give it a fast and fair hearing. I promise I will read your evidence report. Thank you very much, and I will read your words when they come through. I will read your word and wait for confirmation. I will read your book, Mr. Price.	I will... Leave here and I will read your material. Thank you very much, and I will read your words when they come through. But I will read your manuscript today, even if they fire me. I realized that I owed him a lot. I will leave here, and I will read your material. Rest assured I will read your proposal and give it a fast and fair hearing. I will read your book, Mr. Price. I promise I will read your evidence report. I will read your word and wait for confirmation.

I will read your report when I have a spare minute

172,400,000 results on the web

I will read your report when I have a spare time

14,980,000,000 results on the web

More popular!

I will... Leave here and I will read your material.
I realized that I owed him a lot. I will leave here, and I will read your material.
But I will read your manuscript today, even if they fire me.
Rest assured I will read your proposal and give it a fast and fair hearing.
I promise I will read your evidence report.
Thank you very much, and I will read your words when they come through.
I will read your word and wait for confirmation.
I will read your book, Mr. Price.

I will... Leave here and I will read your material.
Thank you very much, and I will read your words when they come through.
But I will read your manuscript today, even if they fire me.
I realized that I owed him a lot. I will leave here, and I will read your material.
Rest assured I will read your proposal and give it a fast and fair hearing.
I will read your book, Mr. Price.
I promise I will read your evidence report.
I will read your word and wait for confirmation.