Conditional Probability: Help Requested on Simple Scenario

#1
Hello Statisticians:

I do marketing for a small manufacturing company, and I'm interested in knowing what the chances are that a customer will have a decline in sales, given that they've already had one year of declining sales. If a customer has a decline from previous years sales it's shown as a Yes along with the year the decline occurred. Vice Versa if there was no decline.

(E.g.) The data for each customer could look like this: 2012: No; 2013: No; 2014: Yes; 2015: No; 2016: No; 2017: No. This data can be represented like, (NNYNNN). Across all companies there were 170 Yes's and 70 No's.

Of the Yes's (signifying a decline in sales for that year), (80x) were a decline with a subsequent increase next year (YN); (40x) were 2 contiguous years of decline (YYN); (27x) were 3 contiguous years (YYYN); (14x) were 4 contiguous years (YYYYN); (6x) were 5 contiguous years (YYYYYN), and finally (3x) were 6 contiguous years (YYYYYYN).

I'd be interested in knowing both what the second year's chances of a decline would be and knowing how to do the calculation all the way up to the 6th year of subsequent declines.

I've been learning about conditional probability, and I'm uncertain as to whether I'm dealing with dependent or independent variables. Any assistance you can provide would be much appreciated!

Thanks,

Mike