Consider a two-dimensional, steady, laminar flow of an incompressible fluid with zero pressure gradient, over a thin horizontal flat plate of length $2\text{ m}$. The free stream velocity is $1\text{ m s}^{-1}$. A boundary layer thickness of $1\text{ mm}$ is observed at a distance of $0.25\text{ m}$ from the leading edge of the plate. At $1\text{ m}$ from the leading edge, the boundary layer thickness (in $\text{mm}$) is _________ (rounded off to the nearest integer).