The provided graphs illustrate the fluctuations in entry costs for national parks and the corresponding visitor numbers from 2011 to 2018.
Overall, there is a notable inverse relationship between the cost of entry to national parks and the number of visitors, with varying trends recorded over the specified years.
In terms of entry costs, the price witnessed significant fluctuations throughout the period in question. Initially set at $10.00 in 2011, the cost escalated steadily to $14.00 by 2013. However, this upward trend was interrupted by a decrease to $12.00 in 2014. Following this dip, the price surged to its peak of $18.00 in 2017, before experiencing a slight reduction to $16.00 in 2018.
Conversely, the visitor numbers to national parks exhibited an overall upward trajectory over the same timeframe, with some variations. Starting at 0.25 million in 2011, the number of visitors rose consistently to reach 0.45 million by 2015. A minor decline occurred in 2016, bringing the total down to 0.40 million; however, this was followed by a resurgence to 0.50 million in 2017. By 2018, the visitor count again saw a slight decline, settling at 0.45 million.