Barbie's first pool leads to more swimsuits

I noticed that in the mid-1970s that Barbie and her friends had a LOT of swimsuits.  I figured out why.  It wasn't just because the summers of that time period were unusually warm, or that sports and leisure really took on greater importance in that decade.  It was because Mattel was selling its first, and in my opinion, still the best, of Barbie's swimming pools, Barbie's Pool Party, sold in 1974 and 1975.
These are the dolls with swimsuits, and the separately sold swimsuits, of those two years:

Dolls

Barbie--1974 Newport

Barbie--1974 SunSet Malibu

Barbie--1975 Gold Medal Swimmer

Barbie--1975 SunSet Malibu

Casey--1975 “Baggie”

Christie--1974 SunSet Malibu

Christie--1975 SunSet Malibu

Francie--1974 SunSet Malibu

Francie--1975 “Baggie”

Francie--1975 SunSet Malibu

Ken--1974 SunSet Malibu

Ken--1975 SunSet Malibu

PJ--1974 SunSet Malibu

PJ--1975 SunSet Malibu

Skipper--1974 SunSet Malibu

Skipper--1975 Gold Medal Swimmer

Skipper--1975 SunSet Malibu

OUTFITS

Barbie—1974 7788 Dazzly Duds for Beach Days

Barbie—1975 7241 Bright N Gay for Holiday Play

Barbie—1975 7271 Gold Medal Olympic swimsuit

Barbie--1975 7424 Regatta on the Sea

Skipper--1974 7878 Beachy Bits for Sunny Fun

Skipper--1975 7725 Gold Medal Olympic Swimsuit