Can you search a transaction by quantity?
There are at least 2 options that I am aware of:


https://www.goochain.net/ 
https://github.com/bitcoin-abe/bitcoin-abe


The first option is a web based tool that will search the block explorer of your choice. The second will take the blockchain and load it into a database which you can search for your desired criteria.

I just ran a test search on goochain with the criteria below and found 26 transactions:

From : 2016-05-03 Tue 03:00 UTC

To     : 2016-05-03 Tue 04:00 UTC

3.1 BTC ≤ Amount ≤ 3.2 BTC