Possible frames with chapter 12

Chapter 12 closes the conversation in Qohelet.

• There are several words used exactly twice in the whole book which have their second usage in chapter 12.
• And there are several that are used 3, 4, 5, 6, 7, 8, etc up to 90 times (asher) where the last time is in chapter 12. 
• There are 33 of 187 words in chapter 12 that only appear once (using my counting scheme and algorithm which I have just 'improved' by looking for prefix before suffix in the simplest 4 letter case.) 
• There appear to my new algorithm to be 101 distinct roots in chapter 12. 
• And there are if I drew them 1,626 connections between chapter 12 words and the rest of the book.  I have 859 connections if I stop at havel - futility which is used 38 times.

So drawing them would require an automation which I don't quite have.  If I limit the list to distinct root and count, I will give you 101 words in 50 table records - almost workable.

The question is - is this deliberate or would it happen at this frequency in any coherent book in any language?

Count	Calculated root of the 101 words used in chapter 12 and at least one other chapter
2	אסף, גשׁם, זהב, ספד, בור, זהר, שׁוב, ישׁב, אנשׁ, צפר, חבל, שׁוק, ישׁר, שׁיר, תפר, אזן, טחן, גע
3	יגע, סוף, קץ, תקן, אור, עפר, משׁל, שׁפל, עב
4	נטע, דר, חור, רחק, ספר, דרך
5	גבה, מעט, חל, המה, עד
6	כסף, קול, שׁב, בקשׁ, סבב, עוד
7	בעל, קהל, זכר, שׁפט, יום
8	חפץ, ירא, שׁמע, בהם, עלם, חשׁך
9	שׁה, שׂר, שׁמר
10	בא, בית , קום
11	לי
12	אחר, הלך, עם
13	ארץ, יתר
14	שׁן, רעה
15	בן
16	נתן
17	אחד, מצא
18	אמר, הכל
19	רבה, דע
20	עשׂ, ים
23	אם
24	רוח
26	וא
29	רא
30	רע
32	דבר
35	שׁמשׁ
37	על, זה
38	הבל, עשׂה
41	אין
42	אל
43	אלה
49	אדם
50	חכם
51	טוב
55	גם
62	לא
69	את
70	כל
87	כי
90	אשׁר