Tokyu 2020 series
Build histories
Table:
Set No.

Manufacturer

Date delivered

2121

J-TREC, Yokohama

November 2017[4]

2122

J-TREC, Niitsu

February 2018[5]

2123

J-TREC, Niitsu

February 2018[7]

Consulting the table information on 'Tokyu 2020 series' in the 'Build histories' section, draft a brief sentence that explains what the highlighted cells show and format it within the following JSON object {"answer": "YOUR ANSWER"}.