The retention rate for teachers since first entering the profession is not available broken down by phase of education. The overall rates are published in Table 8 of the publication, ‘School Workforce in England’, November 2017 and is available at the following link: https://www.gov.uk/government/statistics/school-workforce-in-england-november-2017.
The rate of teachers leaving service each year broken down by phase is available in table 7b of the same publication.
The rates for the latest three years are as follows:
Percentage of teachers leaving state funded schools in England, Full-time equivalent
Source: School Workforce Census
Retention rates for teaching assistants are not held centrally.