Using this matrix, answer the following questions about the period from $2018$ to $2021.$

$\backslash$table$[[2021,(1),(2),(3),(4),(5),(6),(7),(8)],[(1)$ Sales manager,$0\mathrm{.}95,,,,,,,0\mathrm{.}05],[\backslash$table$[[(2)$ Sales$],[$representative$]],0\mathrm{.}05,0\mathrm{.}60,,,,,,0\mathrm{.}35],[(3)$ Sales apprentice,,$0\mathrm{.}20,0\mathrm{.}50,,,,,0\mathrm{.}30],[\backslash$table$[[(4)$ Assist plant$],[$manager$]],,,,0\mathrm{.}90,0\mathrm{.}05,,,0\mathrm{.}05],[(5)$ Production manager,,,,$0\mathrm{.}10,0\mathrm{.}75,,,0\mathrm{.}15],[\backslash$table$[[(6)$ Production$],[$assembler$]],,,,,0\mathrm{.}10,0\mathrm{.}80,,0\mathrm{.}10],[(7)$ Clerical,,,,,,,$0\mathrm{.}70,0\mathrm{.}30],[\backslash$table$[[(8)$ Not in$],[$organization$]],,0\mathrm{.}20,0\mathrm{.}50,0\mathrm{.}00,0\mathrm{.}10,0\mathrm{.}20,0\mathrm{.}30,]]$

Which group of employees were least likely to change positions in the organization between $2018$ an