Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Employee Group | Approximate Number of Employees | Representatives | Status of Agreement |
| --- | --- | --- | --- |
| Southwest Pilots | 8,600 | Southwest Airlines Pilots' Association ("SWAPA") | Amendable September 2020 |
| Southwest Flight Attendants | 14,500 | Transportation Workers of America, AFL-CIO, Local 556 ("TWU 556") | Amendable November 2018 |
| Southwest Ramp, Operations, Provisioning, Freight Agents | 12,800 | Transportation Workers of America, AFL-CIO, Local 555 ("TWU 555") | Amendable February 2021 |
| Southwest Customer Service Agents, Customer Representatives, and Source of Support Representatives | 7,400 | International Association of Machinists and Aerospace Workers, AFL-CIO ("IAM 142") | Amendable December 2018 |
| Southwest Material Specialists (formerly known as Stock Clerks) | 300 | International Brotherhood of Teamsters, Local 19 ("IBT 19") | In negotiations |
| Southwest Mechanics | 2,400 | Aircraft Mechanics Fraternal Association ("AMFA") | In negotiations |
| Southwest Aircraft Appearance Technicians | 200 | AMFA | Amendable November 2020 |
| Southwest Facilities Maintenance Technicians | 40 | AMFA | Amendable November 2022 |
| Southwest Dispatchers | 350 | Transportation Workers of America, AFL-CIO, Local 550 ("TWU 550") | Amendable June 2019 |
| Southwest Flight Simulator Technicians | 50 | International Brotherhood of Teamsters ("IBT") | Amendable May 2019 |
| Southwest Flight Crew Training Instructors | 120 | Transportation Workers of America, AFL-CIO, Local 557 ("TWU 557") | Amendable January 2020 |
| Southwest Meteorologists | 10 | TWU 550 | Amendable June 2019 |
Question:
When will the contract of Southwest with the labor union representing flight attendants become amendable as of December 31, 2017?
Answer:
Amendable November 2018