Similarly, I have data for birth rates of 15 to 17 year olds from 1992-2000. Here is the per-year decline in that rate by president:
Clinton 1.375
Bush 0.75
Obama 1.50
Trump 0.75
Are you saying during Democratic presidents their policies caused the teen birth rate to decline faster than under Republicans presidents and then, when a Republican replaced a Democrat the birth rate continued to decline under the Republican policy but at a slower rate? Remember, it takes a year for a new president's budget and many of his policies to take effect.
What Democratic policy and which Republican policy caused those declines to occur?
It is hard to believe Clinton's liberal leadership caused teens to have less sex or Bush's abstinence policy.
Let's look at the actual teen birth rate rather than the rate of decline. Teenager Girls 15-19: Per 1,000 Women
https://www.statista.com/statistics/259518/birth-rate-among-us-teenagers/
1991-2020. I started with 1993 because it was the first year of the Clinton presidency.
1993: 59
1994: 58.2
1995: 56
1996: 53.5
1997: 51.3
1998: 50.3
1999: 48.8
2000: 47.7
2001: 45
2002: 42.6
2003: 41.1
2004: 40.5
2005: 39.7
2006: 41.1
2007: 41.5
2008: 40.2
2009: 37.9
2010: 34.2
2011: 31.3
2012: 29.4
2013: 26.5
2014: 24.2
2015: 22.3
2016: 20.3
2017: 18.8
2018: 17.4
2019: 16.7
2020: 15.4
Average per presidential term:
Clinton 56.6
Clinton: 49.5
Bush: 42.3
Bush: 40.6
Obama: 33.2
Obama: 23.3
Trump: 17
Democratic Presidents Average: 40.65
Republican Presidents Average: 33.3
Between 1993-2020 the teen birth rate under Democrats averaged 7.35 higher than Republicans.
Based on your conclusions Republican policies resulted in lower teen birth rate then Democrats. Trump's leadership caused the lowest teen birth rates since the data has been kept.
Now, I certainly don't agree with your conclusions that party policies account for these changes in the teen birth rate and I bet you are having problems believing Trump's policies caused the lowest birth rate, but that is the argument that you are making.
As for red and blue states, we both know teen birth rate is related to socio-economic class and the blue states have a higher class with fewer poor minorities than many of the red states.