The graphs below, provided by the CSIRO Oceans and Atmosphere, illustrate the global observations of the impact the Montreal Protocol on the levels of ozone depleting substances in the atmosphere, and suggest the impact into the future to 2050:
Effective Chlorine (all substances) in the atmosphere and the scenario with and without the Montreal Protocol

Source: CSIRO Oceans and Atmosphere
Effective Chlorine (all substances) in the atmosphere

Source: CSIRO Oceans and Atmosphere
Chlorofluorocarbons

Source: CSIRO Oceans and Atmosphere
Methyl bromide and Halons

Source: CSIRO Oceans and Atmosphere
Total Ozone and its relationship with Effective Stratospheric Chlorine

Source: CSIRO Oceans and Atmosphere