December 2018
| Extremely Likely | 74% |
| Likely | 17% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 1% |
| Extremely Unlikely | 4% |
| Don’t know | 1% |
November 2018
| Extremely Likely | 73% |
| Likely | 17% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 2% |
| Extremely Unlikely | 4% |
| Don’t know | 1% |
October 2018
| Extremely Likely | 74% |
| Likely | 16% |
| Neither Likely nor Unlikely | 4% |
| Unlikely | 1% |
| Extremely Unlikely | 4% |
| Don’t know | 1% |
September 2018
| Extremely Likely | 72% |
| Likely | 21% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 0% |
| Extremely Unlikely | 4% |
| Don’t know | 0% |
August 2018
| Extremely Likely | 72% |
| Likely | 21% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 2% |
| Extremely Unlikely | 2% |
| Don’t know | 0% |
July 2018
| Extremely Likely | 72% |
| Likely | 18% |
| Neither Likely nor Unlikely | 5% |
| Unlikely | 2% |
| Extremely Unlikely | 3% |
| Don’t know | 0% |
June 2018
| Extremely Likely | 73% |
| Likely | 20% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 1% |
| Extremely Unlikely | 3% |
| Don’t know | 0% |
May 2018
| Extremely Likely | 72% |
| Likely | 16% |
| Neither Likely nor Unlikely | 3% |
| Unlikely | 4% |
| Extremely Unlikely | 5% |
| Don’t know | 0% |
April 2018
| Extremely Likely | 66% |
| Likely | 21% |
| Neither Likely nor Unlikely | 4% |
| Unlikely | 3% |
| Extremely Unlikely | 6% |
| Don’t know | 0% |