I'm not sure what you're using for US-wide methane and CO2e emissions figures.
Regarding your correction. The percent value is now too low (.002%). I think you used the factor value of ~0.002 as percentage. So you probably meant 0.2% which would be close to my number.
Using your numbers
30000/18200000 = .00164835164835164835 = ~0.16% = ~0.2%
Regarding your correction. The percent value is now too low (.002%). I think you used the factor value of ~0.002 as percentage. So you probably meant 0.2% which would be close to my number.
Using your numbers
30000/18200000 = .00164835164835164835 = ~0.16% = ~0.2%