Montreal Protocol undeveloped to developed nations, the overall level of compliance has been high. Statistical analysis from 2010 show a clear positive signal from the Montreal Protocol to the stratospheric ozone. In consequence, the Montreal Protocol has often been called the most successful international environmental agreement to date. In a 2001 report, NASA found the ozone thinning over Antarctica had remained the same thickness for the previous three years, however in 2003 the ozone hole grew to its second largest size. The most recent (2006) scientific evaluation of the effects of the Montreal Protocol states, "The Montreal Protocol is working: There is
Montreal Protocol (for example, in the past metered dose inhalers commonly used to treat asthma and chronic obstructive pulmonary disease were exempt) or Halon fire suppression systems used in submarines and aircraft (but not in general industry). The substances in Group I of Annex A are: The provisions of the Protocol include the requirement that the Parties to the Protocol base their future decisions on the current scientific, environmental, technical, and economic information that is assessed through panels drawn from the worldwide expert communities. To provide that input to the decision-making process, advances in understanding on these topics were assessed in 1989,