Measles vaccine: relevance

Reductions in measles child-mortality rates from their (1920) peak of 58 per 100,000 per year to a (1970) low of 0.6 per 100,000 per year, a reduction by nearly 99% (see Figure 1), are commonly ascribed to vaccination. If that were clearly the case, then simply by looking at Figure 1, anybody should be able to pinpoint the year in which vaccination became widely used. Is the year of measles vaccine’s first widespread use evident to you from the graph?

[Figure 1]: Measles child mortality 1920 to 1970, Australia.