NASA states that the current levels of Methane are at 0.00019% of the atmosphere.

That is less than 2 parts of Methane per million – negligible traces in the atmosphere.

What does 0.00019% look like in everyday situations?

1.  Imagine an Olympic sized swimming pool – 50 metres X 25 Metres and 2 metres deep representing the atmosphere. Methane would be a small plastic bucket of water added. 
2. Imagine a flight from Auckland to Los Angeles – 10,500 kms. – representing the atmosphere. Methane would be equivalent to getting just halfway through the pushback from the gate at Auckland.

Ruminants of all types (gazelles, camels, giraffes, antelopes, buffaloes, deer, elk, cows and sheep, etc) are responsible for just 15%.  See adjacent diagram from NASA.

New Zealand cows and sheep are just 1% of the world’s ruminants so the contribution that our sheep and cattle are making to Methane content of the atmosphere is minuscule. It is 1% of the 15%.  As stated above all Methane is just 0.00019% of the atmosphere.